Authorities then searched the restaurant and located a "detonated homemade pyrotechnic device", the Police Department stated. Although the bomb exploded on an empty table, no one was hurt in the incident. Police said it was not a pipe bomb, not a Molotov cocktail, had no projectiles, no shrapnel and nothing was ejected.

Authorities say the explosive used was a "homemade pyrotechnic device" containing gunpowder.

"People were jumping over one another, fighting to get over bar stools", he said.

Garrett Gunkle, who was sitting with his wife at the bar, told KNBC-TV there was chaos as customers ran for the exits in the Los Angeles suburb. "The Los Angeles County Sheriff's Department Bomb squad responded to the scene and rendered the device safe.Pasadena Police detectives are now handling the investigation and out of an abundance of caution the federal authorities have been notified".

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Police described the man as being Latino or Middle Eastern, about 6 feet tall, of thin build and with a heavy beard.

Gourdikian said the restaurant received no threats either before or after the explosion. A man dressed in black threw a homemade incendiary device into the crowded California restaurant Thursday at dinnertime, and when it ignited, panicked patrons abandoned their meals and knocked over chairs as they rushed for the exits.

Pasadena Police Detectives is spearheading the investigation, and "out of an abundance of caution", Federal authorities have been notified, police said. He was seen wearing black clothing and a black beanie.

Anyone with information is asked to call Pasadena police at 626-744-4241 or L.A. Regional Crime Stoppers at 800-222-8477.