Residents carry the bodies of several people killed during fighting between Iraq security forces and Islamic State militants on the western side of Mosul, Iraq on March 24, 2017. A U.S. airstrike allegedly killed more than 100 people the previous week.

Felipe Dana / AP file</s>WASHINGTON -- A U.S. airstrike in March killed more than 100 Iraqi civilians by inadvertently setting off a large amount of explosives that Islamic State fighters had placed in a building in Mosul, according to a military investigation made public Thursday.

The Pentagon investigation of the March 17 airstrike put the primary blame on the Islamic State, also known as ISIS, asserting that it placed the explosives in the building and then had two snipers fire at Iraqi forces from the area.

The investigation concluded that 105 civilians were killed: 101 in the building that was bombed and four in an adjacent structure. Thirty-six civilians who were believed to have been in the area have not been accounted for. The toll is one of the highest in the U.S.-led campaign against the Islamic State, though the investigation asserts that jihadis' explosives were mainly at fault.

Neither the U.S.-led coalition nor Iraqi forces were aware that civilians and explosives were in the building, the investigation concluded.

According to the investigation, which was overseen by Air Force Brig. Gen. Matthew Isler, the episode began that March morning when two Islamic State snipers in the city's Jidideh section began firing at troops from Iraq's counterterrorism service, which was fighting its way into west Mosul.

Isler said in a news briefing that his assessment was that the Islamic State deliberately created a situation in which the United States would strike the building and set off the explosions.

The Iraqis did request an airstrike, and the U.S.-led coalition responded by dropping a single GBU-38 munition, which carries about 200 pounds of explosives, about 8:30 a.m.

The goal was to produce a blast that would destroy only the top floor of the building, which was described as a well-built concrete structure, and kill the snipers. The bomb that was dropped, coalition officials said, was not strong enough to have taken down the building.

But the blast set off the explosive material that Islamic State fighters had placed in the structure, causing it to collapse. Analysis of the debris found residue of explosive materials that Islamic State fighters are known to use but that are not used in the GBU-38.

In addition, the investigation said the main damage to the structure was elsewhere in the building from where the GBU-38 was dropped.

According to accounts from neighbors, the civilians went to the building voluntarily because it was one of the best constructed in the area; they took refuge in the basement to get away from the fighting.

The U.S.-led coalition was not aware that civilians had gone there, perhaps because bad weather interfered with reconnaissance in the two days leading up to the strike, Isler said. Nor did Iraqi forces always have a clear view of the area around the building.

The general said it was possible that civilians in the building were held against their will after they took sanctuary, though there is no proof that this is the case. Residents of the adjacent building, which was also damaged, he said, were ordered not to leave the night before the attack.

The airstrike was approved by the command center in Irbil. Isler would not disclose the rank of the officer who approved the strike, but it is usually done by a one-star general.

Isler said the U.S.-led coalition had adjusted its tactics and procedures to prevent a repeat of the episode. But he would not detail them, saying the changes were being kept classified so that the Islamic State would not know them.

The U.S.-led command has previously said 396 civilians have been killed in the more than two-year campaign against the Islamic State in Iraq and Syria, though some independent estimates run much higher.</s>Another 36 unaccounted for in single most deadly incident for civilians since anti-ISIL operations began in 2014.

A US-led air strike in March against a building in the Iraqi city of Mosul killed more than 100 civilians, the Pentagon has said after concluding an investigation into the attack.

The March 17 coalition air strike in al-Jadidah district of Mosul targeted two snipers of the Islamic State of Iraq and the Levant (ISIL) group in the building who had engaged with Iraqi counterterrorism forces, the statement said on Thursday.

Neither coalition nor Iraqi forces knew that the civilians were in the building, nor did they know that ISIL, also known as ISIS, had placed explosives in the building that triggered a secondary explosion, the Pentagon said in a statement.

READ MORE: Coalition says it hit Mosul site where civilians died

The two snipers, 101 civilians sheltered in the bottom floors of the building and four civilians in a neighbouring structure were killed, the statement said.

An additional 36 civilians remain unaccounted for, it said.

The Mosul strike was the single deadliest incident for civilians arising from a coalition strike since anti-ISIL operations in Iraq and Syria nearly three years ago.

The US-led coalition said a local commander ordered the air strike, which was then carried using a single precision-guided bomb.

The Pentagon statement said it was "the most appropriate and proportionate means of engagement to neutralise the threat and to minimize collateral damage".

The statement quoted Major-General Joe Martin, the commanding general of coalition forces, expressing condolences to everyone affected.

"The coalition takes every feasible measure to protect civilians from harm. The best way to protect civilians is to defeat ISIS."

US Air Force Brigadier-General Matt Isler said: "The secondary explosion triggered a rapid failure of the structure which killed the two ISIS snipers, 101 civilians sheltered in the bottom floors of the structure and four civilians in the neighbouring structure to the west."

No condolence payments have been made, Isler said, though such a move has not been ruled out.

The US had previously only acknowledged that it "probably" had a role in the civilian deaths.

The investigation comes amid broader claims that US forces under President Donald Trump are killing more civilians as the military fulfils a plan to "annihilate" ISIL.

As of the most recent US military count at the end of April, a total of 396 civilians had been killed since the beginning of the bombing campaign against ISIL nearly three years ago.

The 105 figure from the March incident would push that number beyond 500.

Airwars, a London-based collective of journalists and researchers that tracks civilian deaths in Iraq and Syria, claims a minimum of 3,350 people have been killed in coalition strikes.</s>WASHINGTON, May 25 (Reuters) - U.S. officials said on Thursday that a military investigation had found that more than 100 civilians were killed after a U.S. air strike on a building in Mosul, Iraq in March.

The investigation concluded that the U.S. strike in the Al-Jadida district inadvertently triggered explosives placed in the building by Islamic State fighters, causing the building to collapse.

It was one of the deadliest single incidents for civilians in recent memory in any major conflict involving the U.S. military, which prides itself on efforts to limit civilian fallout. (Reporting by Idrees Ali)</s>The US military says more than 100 civilians were killed in a blast in Mosul in March.

A Pentagon investigation has found that the civilians were killed when a US airstrike inadvertently triggered a second explosion, causing a building to collapse.

The blast took place on March 17 in the city in the north of Iraq, the report said.</s>A two-month investigation into one of the worst civilian casualty events in decades found that a U.S. military airstrike in Iraq inadvertently set off explosives that ripped through a sprawling apartment block and killed at least 105 civilians.

The deadly March 17 incident in Jadidah, a densely populated neighborhood in the war-torn Iraqi city of Mosul, garnered worldwide attention after photos of smoldering rubble mixed with lifeless bodies rippled across social media.

The Pentagon said military investigators, led by Air Force Brigadier Gen. Matthew Isler, twice visited the site of the airstrike, spoke to witnesses, and pored through more than 700 videos taken from coalition warplanes over a 10-day period before, during, and after the airstrike.

According to the Pentagon account released Thursday, a U.S. military warplane dropped a 500-pound GPS-guided bomb on two Islamic State fighters firing on Iraqi forces from the roof of a building in Jadidah. The investigation said the GBU-38 bomb should have killed the pair and maintained the structural integrity of the two-story building, which was constructed of reinforced concrete and had 30-inch walls at points.

Instead, a massive explosion ripped through the neighborhood, reducing the apartment block to flaming wreckage, twisted rebar, and a tomb for innocent victims, including women and children.

The investigation said 101 bodies were found in a main building and four others were killed in a nearby building.</s>US officials said on Thursday that a military investigation had found that more than 100 civilians were killed after a US air strike on a building in Mosul, Iraq, in March.

The investigation concluded that the US strike in the Al-Jadida district inadvertently triggered explosives placed in the building by Islamic State fighters, causing the building to collapse.

It was one of the deadliest single incidents for civilians in recent memory in any major conflict involving the US military, which prides itself on efforts to limit civilian fallout.

He said 101 civilians in the building were killed, and another four died in a nearby building. He added that 36 civilians remain unaccounted for. The deaths represent about a quarter of all civilian deaths since the US air campaign began.</s>Columbia: A Pentagon investigation has concluded that at least 105 civilians died in an anti-IS strike in the Iraqi city of Mosul in March, officials said Thursday, but they blamed the toll on a secondary explosion of jihadist munitions.

A US aircraft delivered a single precision-guided bomb into a building in west Mosul on March 17, with the aim of killing a pair of snipers on the second story of the structure in the al-Jadida neighborhood, which at the time was under Islamic State control.

But the bomb also caused a large cache of IS explosives to detonate, leading to the catastrophic collapse of the building that had civilians sheltering downstairs, officials said.

"The secondary explosion triggered a rapid failure of the structure which killed the two ISIS snipers, 101 civilians sheltered in the bottom floors of the structure and four civilians in the neighboring structure to the west," said US Air Force Brigadier General Matt Isler, the lead investigator.

Isler said another 36 civilians who are "believed to be connected" to the building remained unaccounted for, but they had likely fled the area shortly before the strike. He said he was "very confident" in the final toll.

It was the single deadliest incident for civilians stemming from a coalition strike since anti-IS operations in Iraq and Syria began nearly three years ago. 

 The United States had previously only acknowledged that it "probably" had a role in the civilian deaths.

The investigation comes amid broader claims that US forces under President Donald Trump are killing more civilians as the military fulfills a plan to "annihilate" the Islamic State group.

The Pentagon denies this and says its rules of engagement remain unchanged and insists its precision-targeting abilities are the best in the world.

Officials say the US takes every precaution to avoid hitting civilians, including by aborting missile strikes at the last moment if a civilian unexpectedly wanders into the target zone.

"Our condolences go out to all those that were affected," said Major General Joe Martin.

"The coalition takes every feasible measure to protect civilians from harm. The best way to protect civilians is to defeat ISIS."

No condolence payments have been made, Isler said, though such a move has not been ruled out.

According to Isler, Iraqi counterterrorism service (CTS) troops had been moving into the al-Jadida neighborhood in west Mosul when they came under fire from the IS snipers.

Mosul was a former IS bastion but the jihadists now only control about 10 percent of the city.

Bad weather had kept surveillance drones from gathering video of the area for two days, and CTS and coalition forces -- not knowing civilians were in the building -- ultimately called in a strike, Isler said.

The precision-guided bomb selected -- a GBU-38 carrying 192 pounds of explosives -- was rigged to cause only localized damage to the building, but it ignited a large amount of ordnance which, unbeknownst to the coalition, IS fighters had previously placed inside.

"Post-blast analysis detected residues common to explosives used by ISIS, but not consistent with the explosive content of a GBU-38 munition," Central Command said in a statement.

"Engineering and weapons analysis indicates that the GBU-38 should have resulted in no more than 16-20 percent damage to the structure, localized to the front of the second floor."

Officials said IS may have deliberately rigged the building to explode and then used the snipers to intentionally provoke an air strike.

As of the most recent Centcom official tally, at least 352 civilians had been killed since the beginning of the bombing campaign against the Islamic State group in Iraq and Syria nearly three years ago.

Airwars, a London-based collective of journalists and researchers that tracks civilian deaths in Iraq and Syria, claims a minimum of 3,350 people have died in coalition strikes.</s>Washington: A U.S. military investigation on Thursday acknowledged that more than 100 civilians were killed in a U.S. air strike on a building in the Iraqi city of Mosul in March during operations against Islamic State militants.

The probe concluded that the U.S. strike in the Al-Jadida district inadvertently triggered explosives placed in the building by Islamic State fighters, causing it to collapse.

Local officials and eyewitnesses have said as many as 240 people may have died in the strike.

It is believed to be one of the single largest incidents of civilian casualties since the U.S.-led coalition started operations against Islamic State in Iraq and Syria.

Air Force Brigadier General Matthew Isler, who oversaw the investigation, told reporters that the March 17 strike was aimed at two Islamic State snipers.

However, the 500-pound bomb triggered explosives inside the concrete building, collapsing it onto civilians.

Isler said the United States and nearby Iraqi forces did not know there were civilians in the building or that it had been rigged with explosives.

He added that 101 civilians inside the building were killed, four civilians were killed in nearby, and 36 civilians were still not accounted for.

Prior to this investigation, the U.S.-led coalition against Islamic State said that at least 352 civilians have been killed in strikes it carried out in Iraq and Syria since 2014. That estimate is far lower than those provided by outside groups.</s>A U.S. military investigation on Thursday acknowledged that more than 100 civilians were killed in a U.S. air strike on a building in the Iraqi city of Mosul in March during operations against Islamic State militants.

The probe concluded that the U.S. strike in the Al-Jadida district inadvertently triggered explosives placed in the building by Islamic State fighters, causing it to collapse.

Local officials and eyewitnesses have said as many as 240 people may have died in the strike.

It is believed to be one of the single largest incidents of civilian casualties since the U.S.-led coalition started operations against Islamic State in Iraq and Syria.

Air Force Brigadier General Matthew Isler, who oversaw the investigation, told reporters that 101 civilians inside the building were killed, four civilians were killed in the neighboring building, and 36 civilians were still not accounted for.

Prior to the March 17 strike, Iraqi forces were about 100 meters away and could see two snipers on the second floor of the building. However, Isler said, there were blind zones and the forces could not see parts of the building.

The coalition had been monitoring the area since the operation for western Mosul began weeks before. However, for two days before the strike took place, the coalition did not have overhead surveillance of the area because of the weather, Isler said.

When the 500-pound bomb was dropped on the building targeting the snipers, it triggered explosives inside the concrete structure, collapsing it onto civilians.

The United States and nearby Iraqi forces did not know there were civilians in the building or that it had been rigged with explosives, the probe found.

“This investigation determined that ISIS deliberately staged explosives and snipers to harm civilians,” Isler said, using an acronym for Islamic State.

He added that the coalition took responsibility for the air strike.

The investigation found that the chemical signature found in the residues was not associated with the bomb used by the United States, but rather with explosives usually used by Islamic State militants.

It said that analysis concluded that the amount of explosives in the U.S. bomb, about 200 pounds, was not enough to bring down the building. The investigation added that the bomb was dropped at the front of the building while structural engineers found that the damage and crater was at the back of the building.

Seven months since the operation to retake Mosul began, Iraqi forces have removed Islamic State from all but a pocket of territory in the western half of Mosul, including the Old City, where the militants are expected to make their last stand.

The investigation recommended the coalition create a team dedicated to assessing civilian casualties that would more quickly investigate reports of civilian deaths.

The coalition has adapted its intelligence gathering tactics to better identify where civilians are located, Isler said.

Prior to this investigation, the U.S.-led coalition against Islamic State said that at least 352 civilians had been killed in strikes it carried out in Iraq and Syria since 2014. That estimate is far lower than those provided by outside groups.
The United States military reports that their investigation found 105 civilians were killed and 36 people are still missing from the bombing of a Mosul building on March 17.