Transit Police are hunting a suspect who attacked the driver of a moving T bus, which then crashed into a line of parked cars, authorities said today.

Investigators released a disturbing video today showing the bus crashing as a passenger physically and verbally assaulted the driver.

Superintendent Joseph O’Connor will hold a press conference at Transit Police headquarters this afternoon to appeal for the public’s help identifying the suspect, who boarded the bus in Chelsea shortly before 9:30 p.m. Sunday with a woman, who can be seen on the video trying to pull the man away from the driver.

The incident occurred on Broadway Street in Chelsea. Police said the bus was in motion when the confrontation caused the driver to veer into a parked car, “which set off a chain reaction involving two additional vehicles,” police said.

Anyone who knows the man’s identity or his whereabouts, or who witnessed the event, is urged to call the Transit Police Criminal Investigations Unit at 617-222-1050.