OAKLAND -- BART police are continuing to search for a man who stabbed another passenger in the arm Sunday night on a Fremont-bound train as it passed through Oakland, authorities said.

Investigators have not established a motive yet for the attack, which left the victim with non life-threatening wounds. He was in stable condition Monday at a hospital.

The stabbing happened about 9:10 p.m. Sunday as the train neared the Lake Merritt station. Police said the victim, whose name, age and place of residence were not released, got off the train at the station and collapsed on the platform.

The train continued on to the San Leandro station before it was stopped by police. Some people were detained as possible suspects but were released after a witness could not identify them, authorities said.

Police believe the suspect may have gotten off the train at either the Fruitvale or Coliseum station.

The train was taken out of service to allow evidence technicians to go over it for clues.

Anyone with information about the stabbing is asked to call BART police at 510-464-7000.