The Pasadena Police Department and the FBI released security video Friday of a man who is believed to have thrown an explosive device into the Cheesecake Factory restaurant in Pasadena in February.

No one was hurt in the Feb. 2 incident. On Friday, authorities showed video of the assailant attempting to discard clothing reportedly worn shortly after the explosion occurred.

At a news conference at Pasadena police headquarters, officials also announced a reward of up to $20,000 for information leading to the arrest and conviction of the man.

Forensic evidence was collected after the incident, but all leads and tips have been exhausted, said Deirdre Fike, FBI assistant director in charge.

The blast occurred at 6:08 p.m. on Feb. 2 at the restaurant at 2 W. Colorado Blvd. Responding officers immediately evacuated the restaurant and located the detonated homemade pyrotechnic device, according to Pasadena police. The Los Angeles County Sheriff's Department Bomb Squad also responded and rendered the device safe, police said.

Video shows the man walking into a nearby grocery store after the explosion, walking with an unusual gait with his feet turned inward.

The motive was not known but Pasadena police Lt. Vasken Gourdikian told NBC4 back in February that nothing in the investigation has suggested the incident was "anything other than a really bad prank." Another police spokesman told NBC4 the device was a "glorified firecracker" that didn't appear to be made to injure anyone.

Witnesses described the suspect as 6 feet tall, with a thin build, a heavy beard, all black clothing and a black beanie.

Anyone with information is asked to call 1-800-CALL-FBI (800-225-5324). Tipsters can remain confidential.