New York ? Seized from a plane about to fly to the Middle East, a Pakistan-born man admitted training to make bombs at a terrorism camp in his native land before he rigged an SUV with a homemade device to explode in Times Square, authorities said Tuesday.

Faisal Shahzad, a naturalized U.S. citizen who recently spent five months in Pakistan, was arrested on terrorism and weapons of mass destruction charges for trying to blow up the crude gasoline-and-propane bomb amid tourists and theatergoers Saturday evening.

He was in custody after being hauled off a Dubai-bound plane at Kennedy Airport that he had been able to board Monday night despite being placed on the federal “no-fly” list. Authorities had planned to arrest Shahzad, who had been under constant watch from mid-afternoon, at his Connecticut home, but lost track of him, two people familiar with the probe told The Associated Press. The people spoke on condition of anonymity because they weren’t authorized to talk publicly about the breach in surveillance.

Because Customs and Border Protection agents were on the lookout for Shahzad, they recognized his name on a passenger manifest and ordered the flight stopped so they could arrest him.

Authorities shed little light on what might have motivated Shahzad — who since moving from Pakistan to Connecticut had acquired a master’s degree in business administration and a house in the suburbs that subsequently was lost to foreclosure. He reportedly came from a background of privilege and wealth — the son of a retired air vice marshal.

A real estate broker who worked with Shahzad in 2004 said the bombing suspect had expressed a dislike for former President George W. Bush and his policy in Iraq.

Attorney General Eric Holder said Shahzad has been providing valuable information to investigators as they sought to determine the scope of the plot. A court hearing for him was canceled Tuesday in part because of his continuing cooperation.

“Based on what we know so far, it is clear that this was a terrorist plot aimed at murdering Americans in one of the busiest places in our country,” Holder said.

Holder and other U.S. officials did not elaborate on whether they believed any international terrorist group was involved, or whether Shahzad, after his training, was acting on his own.

The FBI read Shahzad his constitutional rights after he provided information, and he continued to cooperate, FBI Deputy Director John Pistole said.

Shahzad, 30, had been identified as the man who recently purchased the SUV in cash and was added to the no-fly list early Monday afternoon as a result of breaking developments in the investigation, according to a law enforcement official, speaking on condition of anonymity to discuss an ongoing investigation.

Counterterrorism officials send electronic notifications to airlines when watch lists are updated, but it is up to the airlines to check the web forum where the notifications are sent. If Emirates airlines had done this, the airline would have been able to flag Shahzad when he purchased his ticket that night. Because they didn’t, law enforcement officials were not aware of his travel plans until they received the flight manifest 30 minutes before takeoff, the official said.

Customs and Border Protection officials, who were on the lookout for Shahzad since the early afternoon, recognized his name on the manifest and ordered the flight stopped so they could arrest him. The flight had not left the gate at that point, the official said.

Homeland Security Secretary Janet Napolitano credited Customs officials with recognizing Shahzad’s name on the manifest and stopping the flight. But she had little explanation for how he was able to board the plane with a last-minute ticket.

According to the criminal complaint filed in federal court in Manhattan, Shahzad confessed to buying the SUV, rigging it with a homemade bomb and driving it into Times Square. The complaint says he admitted to receiving bomb-making training in Waziristan, Pakistan, a region where the Pakistani Taliban operates with near-impunity.

The Pakistani Taliban has claimed responsibility for the bomb plot, but U.S. officials say there’s no evidence to back that up.

The complaint charged Shahzad with trying to detonate a weapon of mass destruction, attempted car bombing and obstructing interstate and foreign commerce by trying to kill and maim U.S. citizens.

The report of Shahzad’s training raises the possibility the attack was a coordinated international effort, but authorities have not said whether they believe that to be the case.

In Pakistan, authorities said they had detained several people in connection with the bombing attempt, although the FBI said it had no confirmation that these arrests were relevant to the case. Reports also surfaced in Pakistan that Shahzad came from a wealthy family and was the son of a former high-ranking air force officer.

President Barack Obama said “hundreds of lives” may have been saved Saturday night by the quick action of ordinary citizens and law enforcement authorities who saw the smoking SUV — a 1993 Nissan Pathfinder — parked in Times Square.

“As Americans and as a nation, we will not be terrorized. We will not cower in fear. We will not be intimidated,” Obama said.

Married with two children, Shahzad had obtained U.S. citizenship after emigrating from Pakistan.

In Bridgeport, Conn., authorities removed filled plastic bags and a bomb squad came and went from a house in a working-class neighborhood of multifamily homes. FBI agents found a box of consumer-grade firecrackers and other fireworks in the driveway that they were marking off as evidence.