French police set off explosions in standoff Updated at 8:23 p.m. (CBS/AP) TOULOUSE, France - Riot police set off explosions outside an apartment building early Thursday in an effort to force the surrender of a gunman who boasted of bringing France "to its knees" with an al Qaeda-linked terror spree that killed seven people. Hundreds of heavily armed police, some in body armor, cordoned off the five-story building in Toulouse where the 24-year-old suspect, Mohamed Merah, had been holed up since the pre-dawn hours. As midnight approached, three explosions were heard and orange flashes lit up the night sky near the building. Authorities said the shooter, a French citizen of Algerian descent, had been to Afghanistan and Pakistan, where he claimed to have received training from al Qaeda. This undated and unlocated frame grab provided Wednesday, March 21, 2012, by French TV station France 2 shows Mohammad Merah, the suspect in the killing of 3 paratroopers, 3 children and a rabbi in recent days in France. French police were preparing to storm an apartment building in Toulouse on Wednesday to arrest a holed-up gunman who is suspected in seven killings and claiming allegiance to al-Qaida, a top police official said. Credit: AP Photo/France 2 They said he told negotiators he killed a rabbi and three young children at a Jewish school on Monday and three French paratroopers last week to avenge the deaths of Palestinian children and to protest the French army's involvement in Afghanistan, as well as a government ban last year on face-covering Islamic veils. "He has no regrets, except not having more time to kill more people and he boasts that he has brought France to its knees," Paris Prosecutor Francois Molins told a news conference. The standoff began when a police attempt at around 3 a.m. to detain Merah erupted into a firefight. Three police were wounded, triggering on-and-off negotiations with the suspect that lasted into the night. As darkness fell, police cut electricity and gas to the building, then quietly closed in to wait out the suspect. Authorities were "counting on his great fatigue and weakening," said Didier Martinez of the SGP police union, adding the siege could go on for hours. Street lights were also cut, making Merah more visible to officers with night vision goggles in case of an assault. French authorities -- like others in Europe -- have long been concerned about "lone-wolf" attacks by young, Internet-savvy militants who self-radicalize online since they are harder to find and track. Still, it was the first time a radical Islamic motive has been ascribed to killings in France in years. Merah espoused a radical brand of Islam and had been to the Afghanistan-Pakistan region twice and to the Pakistani militant stronghold of Waziristan for training, Molins said. He said the suspect had plans to kill another soldier, prompting the police raid. The gunman's brother and mother were detained early in the day. Molins said the 29-year-old brother, Abdelkader, had been implicated in a 2007 network that sent militant fighters to Iraq, but was never charged. Official: French suspect sought more bloodshed Fears racist killer on loose in France The suspect repeatedly promised to turn himself in Wednesday, then halted negotiations. Cedric Delage, regional secretary for a police union, said police were prepared to storm the building if he did not surrender. After bouts of deadly terrorist attacks in France in the 1980s and 1990s, France beefed up its legal arsenal -- now seen as one of the most effective in Western Europe and a reference for countries including the U.S. after the Sept. 11 attacks. Sarkozy's office said President Barack Obama called him Wednesday to express condolences to the families of the victims and praise French police for tracking down the suspect. The statement said France and the United States are "more determined than ever to fight terrorist barbarity together." In recent years, French counterterrorism officials have focused mainly on al Qaeda in the Islamic Maghreb, the North African affiliate of Osama Bin Laden's network that has its roots in an insurgent group in Algeria, a former French colony. Molins said Merah's first trip to Afghanistan ended with him being picked up by Afghan police "who turned him over to the American army who put him on the first plane to France." An Interior Ministry official, speaking on condition of anonymity, said Merah had been under surveillance for years for having "fundamentalist" Islamic views.