Authorities are searching for a man they say detonated a homemade explosive device inside a crowded restaurant in Old Town Pasadena and ran away Thursday night.
The device created heavy smoke when it went off at the Cheesecake Factory on West Colorado Boulevard, but no injuries were reported, the Pasadena Police Department said in a statement.
Pasadena police and the Los Angeles County Sheriff's Department bomb squad responded to a report of an explosion at the restaurant just after 6 p.m.
Witnesses described the suspect as about 6 feet tall, with a thin build and heavy beard, according to police. He was wearing all black clothing and a black beanie.
The man opened the door and tossed the device inside before running from the scene, witnesses told KABC-TV.
Federal authorities were notified "out of an abundance of caution," police said.
Lourdes Arocho, an FBI spokeswoman, said local authorities were handling the investigation.
The crime is not considered to be an act of terrorism, according to a police source who was not authorized to speak publicly on the matter. The device would have made a very loud noise, but was not considered to be a true improvised explosive device, they said.
Anyone with information is urged to call the Pasadena police at (626) 744-4241.
12:40 p.m.: This article was updated with comments from a law enforcement source.
Noon: This article was updated with contact information for police.