U.S. Attorney General Eric Holder said Monday investigators have made progress into a failed car bombing attempt in New York, while Homeland Security chief Janet Napolitano said they rule no suspect out as claim of responsibility emerged and dismissed.

Holder said investigators made "really substantial progress," in the probe with "some good leads." He said the investigation will be successful and the perpetrators who put a car bomb in New York's Times Square "will be found and brought to justice."

A smoking dark green Nissan Pathfinder SUV was left with its engine running and hazard lights flashing about 6:30 p.m. (EDT) on the tourist magnet of Times Square Saturday. Thousands of people were evacuated and nearby buildings emptied.

The car contained a potentially deadly explosive device, but it failed to explode. Investigators were able to search the car for forensic evidence that could lead to the ones responsible. Security cameras around the square revealed the driver who left the car there was a man in his 40s.

The Pakistani Taliban on Sunday posted a video online to claim responsibility for the attempt. The claim was dismissed by New York Mayor Michael Bloomberg and Police Commissioner Ray Kelly.

New York's Peter King, top Republican on the House Homeland Security Committee, also said there doesn't appear to be any foreign connection to the bombing attempt.

However, federal officials were more cautious, Napolitano on Monday told NBC's "Today" that no suspect has been ruled out, and cautioned against "premature decisions one way or another."

"Right now, every lead has to be pursued," said she. Holder also said it was too early to say who was responsible.