Two 17-year-old males were stabbed Friday morning on a northbound Broad-Ridge Spur train after it left the Erie station, and one was critically wounded, officials said.

The stabbing occurred shortly before 9 a.m., and the teenagers got off at the Olney station before walking to Einstein Medical Center, a quarter of a mile from the station, police said.

One teenager was stabbed once in the left side of the abdomen and was in stable condition. Police said they were unable to determine where the critically injured teenager had been stabbed. The attacker exited at Olney, re-entered the station, and took a southbound express, according to SEPTA.

On Friday evening, SEPTA released two images from agency surveillance video showing a man officials alleged was the assailant. In the images, the man appears to be wearing a silver-colored jacket and a blue wool cap with white trim, and is carrying a pack of cigarettes.

Right before the stabbing, a fight broke out on the train, said SEPTA spokesperson Carla Showell-Lee. Details were not immediately available. There were no injuries to other passengers on the train, she said, adding that she could not elaborate on how many people witnessed the incident.

There were no delays because of the incident, said John Golden, another SEPTA spokesperson.