This article is by Mark Mazzetti, Sabrina Tavernise and Jack Healy.

A Pakistani-American man arrested in the failed Times Square car bombing has admitted his role in the attempted attack and said he received explosives training in Pakistan, the authorities said Tuesday.

The man, Faisal Shahzad, 30, was arrested as he tried to flee the country in a Dubai-bound jet late Monday. Hours later, there were reports that seven or eight people had been arrested in Pakistan, as officials in both countries sought to determine the origins and scope of the plot.

Mr. Shahzad was charged on Tuesday with several terrorism-related crimes. American intelligence officials said that while any ties Mr. Shahzad had to international terrorist groups remained murky, investigators were strongly looking at possible links to the Pakistani Taliban in the attempted attack on Saturday.

If the role is confirmed, it would be the group’s first effort to attack the United States and the first sign of the group’s ability to strike targets beyond Pakistan or Afghanistan.