NEW YORK — The Pakistani-American who police say admitted to igniting a failed car bomb in busy Times Square has made no court appearance since his arrest early this week and, though he is cooperating, authorities remain unsure he was acting alone.

New York City Police Commissioner Raymond Kelly declined Friday to discuss what Faisal Shahzad is telling investigators, including what his motives were. He was arrested Monday aboard a Dubai-bound plane two days after the nighttime bomb scare cleared several blocks of the bustling district.

"This individual is cooperating. In these types of situations, you let the information flow, so to speak," Kelly said.

Police have surveillance images of Shahzad around Times Square and video that shows his car traveling to the spot where they say he left a smoking sport utility vehicle May 1 rigged with a gasoline-and-propane bomb.

Law enforcement officials say they are trying to find links between the Bridgeport, Conn., man and possible financing sources, including the Pakistani Taliban, which has both claimed responsibility for and denied roles in the botched bombing.

A money courier was being sought who may have funneled cash to the 30-year-old budget analyst, a law enforcement official told The Associated Press. The official spoke on condition of anonymity because of the sensitivity of the investigation.

Shahzad has told investigators that he trained in the lawless tribal areas of Waziristan, where both al-Qaida and the Pakistani Taliban operate, and that he came up with the attack plan himself.

Investigators have not been able to establish whether Shahzad was recruited for the Times Square operation by the Pakistani Taliban or another militant group — or whether Shahzad came up with the attack plan himself, the official said.

Since the bomb scare in the heart of the city, false-alarm calls are up dramatically, nerves are jangled, and media and law enforcement are rushing to the scenes to make sure the reports aren't something bigger.

More than 600 calls have come in since the attempted car bombing a week ago — about 30 percent higher than normal, police said.

Times Square vendor Walter "Candyman" Wells said the constant scares aroused more suspicion.

"I think they're testing us, whoever is doing this," Wells said, sitting on a stool near his table of T-shirts. "They're playing chess with us right now, but they ain't gonna win. 'Cause we're the Bobby Fischers."