NEW YORK, New York (CNN) -- The New York Police Department has released photos of a bicycle and a suspect in Thursday's Times Square recruitment center bombing.

The photo of the suspect, extracted from surveillance footage and released on Friday, shows someone riding a bicycle away from the scene shortly after the explosion. The second photo shows a metallic blue bicycle that was found abandoned in trash nearby.

Authorities are offering a $12,000 reward for information in that leads to an arrest in the case.

The explosion, which caused no injuries, went off about 3:45 a.m. Thursday at an Armed Forces Recruitment center in Times Square.

Authorities were re-examining an incident that happened last month at the U.S.-Canadian border, New York Police Commissioner Ray Kelly told CNN Friday. Watch new evidence in Times Square bombing case »

A car with three people was halted as it crossed from New York into Canada, a senior U.S. government official told CNN, and the car was searched as a matter of routine, the official said.

Anarchist-type material was found, the official said, and in a backpack, agents found pictures of New York, including ones of Times Square, at least one of which showed the recruiting station.

The people told authorities that they had been visiting New York City for a week. At some point, two of the three -- both men -- ran off.

The Canadians then forwarded the information to the New York police liaison officer in Canada, who alerted police. However, it was eventually determined by the Canadians and NYPD that the incident posed no threat.

The official said he strongly doubts a connection will be found between the information garnered from that incident and the Times Square bombing.

On Friday, Kelly acknowledged the incident.

"That stop did take place in Canada," he said. "Some pictures of Times Square, including the recruiting, station were found. Our liaison officer in Montreal was notified."

He said, "Our teams of detectives that go around and talk to businesses did go out and speak to the people in the recruiting station and told them about the fact that these pictures were found. So federal officials are going back to take another look and attempting to speak to Canadian officials about that stop."

Asked whether the attack could be linked to two other unsolved blasts in New York -- one at the British consulate in 2005 and the other at Mexican consulate in 2007, Kelly said, "There is certainly a possibility."

"The times are very similar," he said. "All three incidents took place with an individual on a bike, leaving a bomb. So, that's a possibility."

Meanwhile, a person who was questioned in Los Angeles about letters that members of Congress received after the explosion in Times Square were "not involved" in the bombing, the law enforcement source told CNN.

"It's an ugly coincidence," the source said, referring to the timing of the bombing and the appearance of the letters. "He is not the bomber."

On Thursday afternoon, just a few hours after the blast, authorities in Washington said several members of Congress had received letters that raised concern.

The letters contained photos of a man standing in front of the recruiting center along with the statement "We did it," according to an e-mail from a senator's office.

Fewer than 10 letters were received by members of Congress, a law-enforcement source said. All the letters were received by Democrats, another law enforcement source said. E-mail to a friend

CNN'S Kevin Bohn

All About Canada • New York City Police Department • Times Square