CLOSE CALL: After the Northwest Airlines flight was evacuated in Detroit, a bomb squad member (above) scoured the craft, while fliers Zan Jafry and dad Syed Jafry (inset) breathed a sigh of relief.WDIV-TV

An al Qaeda terrorist tried to blow up a plane packed with Christmas travelers yesterday as it was about to land in Detroit — but was thwarted by heroic passengers who tackled the madman, authorities said.

The 23-year-old Nigerian suffered serious burns, and at least two other passengers were injured in the terrifying violence aboard the Northwest Airlines flight from Amsterdam.

“This could have been catastrophic,” Rep. Peter King (R-LI) told Fox News. “We were lucky.”

President Obama, on vacation in Hawaii, ordered his national security team to ensure that “all appropriate measures be taken to increase security for air travel,” the White House said.

That will result in extensive travel delays through the holidays.

The would-be bomber, Abdul Mutallab, began his jihad journey by boarding an Amsterdam-bound KLM jet in Lagos, Nigeria. He changed in the Dutch capital to the Northwest Airbus, said King, the senior Republican on the House Homeland Security Committee.

Mutallab — flying on a one-way ticket, according to MSNBC — is an engineering student at University College of London and was coming to the US for a religious seminar.

After his arrest, he told authorities he was given an explosive powder in Yemen — and orders from al Qaeda to blow up the plane over US soil, ABC said.

Michigan Rep. Pete Hoekstra, the senior Republican on the House Intelligence Committee, said the suspect may have had contact with a radical imam, Anwar Al Awlaki, who has ties to the suspected shooter in the Fort Hood killings.

As the plane, carrying 289 passengers and crew, began its descent, Mudallad emerged from the bathroom carrying a pillow over his stomach, according to Detroit TV station WDIV.

He then tried to detonate the powder — taped to his groin — by mixing in chemicals from a syringe, CBS News said.

The device misfired but spewed smoke and flames, passengers said.

“It sounded like a firecracker in a pillowcase,” said Peter Smith of the Netherlands. “First there was a pop, and then [there] was smoke.”

Another passenger, Stephanie van Herk, told the Wall Street Journal she saw flames leap up from the suspect’s lap. “It was higher than the seat,” she said.

Passengers and crew members yelled for water and fire extinguishers as the bumbling bomber desperately tried to pull down his flaming pants.

They shouted: “What are you doing? What are you doing?” van Herk said.

Syed Jafry, who was three rows behind the suspect, said another “young man behind me jumped on him.

The ordeal ended when “a sturdy guy put a lock on [Mutallab’s] head,” and dragged him to the front of the plane, Veena Saigl, told the Detroit Free Press. Mudallad’s “pants were down,” she said.

“It was terrifying,” another passenger, Richelle Keepman, told CNN. “We all thought we weren’t going to land, we weren’t going to make it.”

Flight 253 — which bore the Delta name because the two airlines merged — arrived safely at 11:53 a.m. It taxied to a remote part of the airport and everyone aboard were taken off and questioned.

The suspect was cuffed to a stretcher and taken to the University of Michigan Hospital in Ann Arbor.

“He was burned very severely on his leg,” passenger Melinda Dennis told the Detroit Free Press.

“He was very calm and didn’t show any reaction to pain.”

Mutallab was not on a “no-fly” list of suspected terrorists — but was known to authorities, King told Fox News.

“My understanding is . . . that he does have al Qaeda connections, certainly extremist terrorist connections, and his name popped up pretty quickly” in the search of intelligence databases, he said.

King said the device was “fairly sophisticated” — an explosive that “appears to be different from what we’ve encountered before.”

Mutallab had a two-year visa allowing him to stay in the United States though June 16, 2010.

“I would say we dropped the ball,” King added.

He told Fox that Nigeria is “a center of concern,” and Homeland Security “reached out” to authorities there asking for improved airport screening about a year ago.

Authorities want to determine whether the terrorist attempt was part of a larger plot. There is a “worldwide alert to make sure this is not part of a larger overall scheme,” said King.

NBC said Mutallab “claims to have been acting on his own.”

The violence bore an eerie resemblance to the 2001 bombing attempt by terrorist Richard Reid — which also took place around Christmas.

Reid, now serving life in the federal “supermax” prison, tried to detonate an explosive that had been packed into his gym shoes.

In that case, a flight attendant and a passenger subdued him.

The Department of Homeland Security said passengers will see additional screening measures on domestic and international flights because of yesterday’s incident, but officials are not preparing to raise the terrorism alert level.