WASHINGTON -- Law enforcement officials say the Pakistani-born U.S. citizen suspected in the failed attempt to explode a bomb-laden car in Times Square had attended a terror training camp in Pakistan.
Faisal Shahzad was arrested late Monday aboard a flight that was headed to the Middle East for trying to blow up the sport utility vehicle Saturday evening.
One Washington official said Tuesday that Shahzad told the FBI about his training. Attorney General Eric Holder said Shahzad had admitted his role in the attempted bombing and was providing valuable information to interrogators, but Holder would not elaborate.
A second official said the camp was in the lawless tribal region of Waziristan, where the Pakistani Taliban operates with near impunity.
The group has claimed responsibility for the attack, but officials say there's no evidence to back that up. Both officials spoke on condition of anonymity to discuss the investigation.
Shahzad was on board a Dubai-bound flight that was taxiing away from the gate at Kennedy Airport when the plane was stopped and FBI agents and New York Police Department detectives took him into custody late Monday.
The U.S. attorney's office in Manhattan was handling the case and said Shahzad would appear in court later Tuesday.
In Karachi, Pakistani authorities said Tuesday they had detained at least one man in connection with the Times Square bombing attempt. Two intelligence officials said the man, identified as Tauseef, was a friend of Shahzad.
Media reports said other were detained, including relatives of Shahzad.
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 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.
Shahzad, 30, had recently returned from a five-month trip to Pakistan, where he had a wife, according to law enforcement officials who spoke to The Associated Press on condition of anonymity because of the sensitivity of the investigation.
Shahzad became a naturalized U.S. citizen last year shortly before traveling to Pakistan, a federal law enforcement official in Washington said, speaking on condition of anonymity amid the ongoing investigation.
Investigators hadn't established an immediate connection to the Pakistani Taliban -- which had claimed responsibility for the botched bombing in three videos -- or any foreign terrorist groups, a law enforcement official told the AP.
"He's claimed to have acted alone, but these are things that have to be investigated," the official said.
Another law enforcement official said Shahzad was not known to the U.S. intelligence community before the failed bombing attempt, in which authorities found a crude bomb of gasoline, propane and fireworks in a 1993 Nissan Pathfinder parked on a bustling street in Times Square.
Shahzad graduated from the University of Bridgeport in Connecticut with a bachelor's degree in computer applications and information systems in 2000 and later returned to earn a master's of business administration in 2005, the school said.
FBI agents searched the home at a known address for Shahzad in Bridgeport early Tuesday, said agent Kimberly Mertz, who wouldn't answer questions about the search.
Authorities removed filled plastic bags from the house in a mixed-race, working-class neighborhood of multifamily homes in Connecticut's largest city. A bomb squad came and went without entering as local police and FBI agents gathered in the cordoned-off street. FBI agents appeared to have found fireworks in the driveway that they were marking off as evidence.
He used to live in a two-story grayish-brown colonial with a sloping yard in a working-class neighborhood in Shelton. The home looked as if it had been unoccupied for a while, with grass growing in the driveway and bags of garbage lying about.
Law enforcement officials say Shahzad bought the Pathfinder from a Connecticut man about three weeks ago and paid cash.
The SUV was parked near a theater where the musical "The Lion King" was being performed. The bomb inside it had cheap-looking alarm clocks connected to a 16-ounce (454-gram) can filled with fireworks, which were apparently intended to detonate gas cans and set off propane tanks in a chain reaction "to cause mayhem, to create casualties," police Commissioner Raymond Kelly said.
Police said the SUV bomb could have produced "a significant fireball" and sprayed shrapnel with enough force to kill pedestrians and knock out windows.
A vendor alerted a police officer to the parked SUV, which was smoking. Times Square, clogged with tourists on a warm evening, was shut down for 10 hours. A bomb squad dismantled the bomb and no one was hurt.
Contributing to this report were Associated Press writers Eileen Sullivan, Pete Yost and Julie Pace in Washington, Sara Kugler in New York, Chris Brummitt in Islamabad, Ashraf Khan in Karachi, Adam Schreck in Dubai, AP Video journalist Ted Shaffrey and writer John Christoffersen in Bridgeport, Connecticut; and AP photojournalist Doug Healey in Shelton, Connecticut.