Getty Images Police guard the perimeter of Times Square on Sunday.
A failed car bomb smoked, popped and shut down Times Square, causing panic, evacuations and confusion Saturday on one of the tourist spot's busiest nights. Most of the streets in the area were reopened Sunday morning, though a heavy police presence remained in the area.
New York Police Commissioner Ray Kelly said officers are heading to a town in Pennsylvania to talk to a man who believes he may have recorded a bombing suspect on his video camera. Police are looking a for a white male in his 40s who was seen shedding a dark shirt with a red shirt underneath, he said at an afternoon press conference. Investigators are now looking through "hundreds of hours of surveillance videos," Mr. Kelly added.
On Sunday, a Pakistani Taliban group took credit for the attempted attack in a short video. The video, purportedly from the Tehrik-e-Taliban Pakistan group, offered "congratulations to the Muslim ummah (community) on the jaw-breaking blow to Satan's USA." The video, which made no mention of the plot's failure, said the attack was a response to recent killings of top Pakistani Taliban figures, including Baitullah Mehsud.
Mr. Kelly said there is no evidence of a Taliban link to the attempted bombing and noted that the group had falsely claimed responsibility for other incidents in which it had no involvement.
"The intent was to cause mayhem," he said.
Authorities said a Nissan Pathfinder at West 45th Street and Seventh Avenue was left Saturday night loaded with a bomb made from two clocks, three propane gas tanks, two additional one-gallon gas canisters and fireworks.
"It appeared that [the bomb] was in the process of detonating and malfunctioned," said police spokesman Paul Browne.
A street vendor alerted a policeman on mounted patrol—Wayne Rhatigan, 47 years old, a 19-year-veteran of the force. In an interview, Mr. Rhatigan said he smelled gunpowder coming from the vehicle and went toward it, thinking it could explode at any second. He grabbed two other officers to help move people away from the smoking Pathfinder as he called for backup at 6:34 p.m.
Police blocked the area from West 43rd to 47th streets along Broadway and Seventh Avenue with metal railings. Parts of West 48th Street were also closed. Most of the streets were reopened Sunday morning after police removed the Pathfinder.
View Slideshow Mustafah Abdulaziz for The Wall Street Journal Onlookers lined police barracade early Sunday morning in Times Square.
Police later said the Pathfinder was spotted on security video at 6:28 p.m. The video wasn't clear enough to identify the driver and no videos have been found showing the suspect in the attack, police said.
Pakistani Group Claims Credit
The Middle East Media Research Institute first reported the discovery of an online video claiming responsibility for the attempted car bombing in Times Square.
The video shows a montage while an unseen person speaks in Urdu. The speaker is allegedly Qari Hussain Mehsud, a spokesman for the Pakistan Taliban, formally known as the Tehrik-i-Taliban Pakistan. The video does not specifically refer to the Times Square incident, describing it only as "this attack."
Marc Sageman, a terrorism expert and former Central Intelligence Agency officer in Pakistan, said the Pakistan Taliban has a history of claiming responsibility for events they had nothing to do with. He said the group falsely claimed credit for a series of blackouts that hit the northeast several years ago and for a mass shooting in upstate New York last year.
"Everything should be looked at skeptically unless you have pretty strong evidence one way or another," Mr. Sageman said.
In a statement, the IntelCenter think tank said if the Pakistan Taliban's claims were confirmed, it would be their first attack against a target in the U.S.
More Videos Police Defuse Bomb in SUV
The Times Square scare is the latest in a series of attacks and attempted attacks on the U.S. over the past year that has counter-terror experts concerned about a possible shift in terrorist tactics to embrace small-scale strikes that are harder to identify and prevent.
Over the past year, on at least eight different occasions, people linked to radical Islamic thought attempted to carry out or carried out attacks on targets inside the U.S. That includes the failed Christmas Day bombing on board a Detroit-bound airliner, the shooting rampage at Ft. Hood in Texas, three separate bomb plots foiled by the Federal Bureau of Investigation last September, and a handful of earlier plots broken up last spring and summer.
Investigation Traces Plates to Connecticut
Earlier Sunday morning, however, New York officials had no information on those responsible for the attempted attack. "We have no idea who did this or why," said Mayor Michael Bloomberg, alongside Mr. Kelly at a Times Square news conference. The mayor called the bomb "amateurish."
Investigators said that the vehicle's Connecticut license plates didn't match the make of the car. The license plate's last known location was Kramer's Used Auto Parts in Stratford, Conn., according to a law enforcement official familiar with the investigation. No one answered the phone there Sunday.
Police said the bomb parts and an additional locked metal box would be removed to the NYPD Rodman's Neck firing range in the Bronx.
New York as Terror Target Terrorist activity in New York since the Sept. 11 attacks. View Interactive More photos and interactive graphics
Homeland Security chief Janet Napolitano echoed Mr. Bloomberg's comments, saying Sunday on Fox News that the bomb appeared to be an "amateurish" terrorism attempt.
Ms. Napolitano said the Federal Bureau of Investigation, the Department of Homeland Security and the city of New York were investigating the incident, including examining the car, tracing fingerprints and looking at video from the area around the bomb.
"There are a lot of cameras in that area," she said, adding that there's "a lot of activities in terms of investigation."
Ms. Napolitano said there was no information to suggest that any other sites had been targeted in Saturday's car bomb attempt. Evidence so far suggested this was a "one-off attempt," she said.
Mr. Bloomberg earlier said that no other hazards were found and that "there's no more danger here than in any other city." Further, no credible threats were made by organized groups with regards to the attack, police said.
President Barack Obama had been briefed on the bomb. In a statement, the administration said that the president, who attended an annual dinner for White House news correspondents Saturday night, praised the response by the New York Police Department. The president has also directed his homeland security and counterterrorism adviser, John Brennan, to advise New York officials that the federal government is prepared to provide support, the Associated Press reported.
'Everyone Started Running'
Street vendor Larry Franklin, 56, said a friend reported a man to police who put keys in the black SUV and walked away. His friend told him smoke began coming out of the back and police rushed to the scene.
"I looked back and boom," said Matthew Fox, 44, a street vendor. "Everyone started running and women started screaming." He said he was "10 blocks away from 9/11 when it happened," but that "this wasn't anything like that."
Nineteen-year-old Ivan Morrison, who was in town from Vermont to see "The Addams Family," said "it sounded like a deeper gun shot."
View Full Image Getty Images A picture is displayed of an alarm clock found in a dark SUV which is said to be in the vehicle with a bomb that was discovered before it could be detonated in Times Square.
Subway service on many lines was suspended or delayed. On Broadway, "God of Carnage" and "A Behanding in Spokane" each began 30 minutes late, show officials said. The evening performance of "The Lion King" was performed as scheduled. Early reports erroneously said that the show had been canceled.
About 11 hours after the attempted attack, the streets of normally bustling Times Square were reopened and tourists again began pouring back into the area, many of them taking the incident in stride.
Honeymooners Lorenz Inglin, 31, and his wife Claudia, 27, who had traveled to New York from Zurich, Switzerland, said they lingered in Times Square to soak up the scene of police and a traffic jam of people, thinking whatever had happened was likely a hoax. "If we had known this was a real threat we wouldn't have stayed and watched it," said Mr. Inglin.
But they weren't planning to cut short their visit or avoid New York in the future. "We are aware that terrorists could happen anywhere," he said. "We always have the eyes open."
—Sophia Hollander, Ian Talley, Joseph De Avila and the Associated Press contributed to this article
Write to Ellen Gamerman at ellen.gamerman@wsj.com
Archive photo of Times Square. 
A car containing a bomb was discovered in , New York City, causing the evacuation of streets surrounding the area. 

Reports say the vehicle, a , parked outside a theatre on 45th Street and Seventh Avenue, had smoke coming out of the back at around 6:30 p.m EDT (10:30 p.m. UTC). Unconfirmed reports say an unknown man ran away from the car. A roughly square area of the city, its boundaries formed by 43rd and 48th Street and 7th and 8th Avenue, was evacuated.

The  bomb squad was called in and were able to retrieve the package using a . Officials removed , consumer-grade , two five-gallon cans of gasoline, three propane tanks, electrical wiring, and two clocks with batteries that apparently were fashioned as one or two . The bomb has been described as "amateurish". No casualties or injuries were reported.

As of yet police have not named a suspect and are reviewing security footage. The car used by the suspect was  and had a non-matching license plate; the legitimate owner of the plates does not appear to have been involved in the incident.

President Barack Obama has congratulated the speediness with which the New York Police Department responded.

New York has been in a state of constant alert since the  that occurred on September 11, 2001. In September 2009, a plot to attack the  with  was uncovered by police. In December 2009, Times Square was evacuated due to a illegally parked van, although it contained no explosives. On March 6, 2008, a small bomb was set off in front of the United States armed forces recruiting station in .