By Martin Finucane, Globe Staff

The union that represents thousands of MBTA workers says an attack on a bus driver by more than a dozen teens underlines the need to crack down on assaults on public transit workers.

“The Boston Carmen’s Union ATU Local 589 is relieved and thankful that the Bus Driver, attacked in the early morning hours, was not more seriously injured. However this assault by a reported mob on an isolated Local 589 member simply doing his job illustrates the need for public safety officials and the legislature to act quickly before a transit worker is killed,” the union’s president, John Lee, said in a statement.

Lee called for “immediate action” on a bill that was crafted by the union along with MBTA Transit Police. The bill would allow police officers to arrest people if the officers have probable cause to believe the suspects have committed assault and battery on a public employee or health care worker.

Officers summoned to the scene of an assault now can only hand out a summons to a suspect, said MBTA Transit Police Superintendent-in-Chief Joseph O’Connor.

“It would give our officers a stronger tool when investigating these types of assaults on scene,” he said. “Currently, officers respond and the strongest action they can take is a summons.”

“This will allow us to expedite the process and get individuals who assault MBTA employees into the criminal justice system,” he said.

Lee, the union president, said it was “time for a crackdown on the thugs that target working women and men on any public transit job.”

The attack on the driver happened early Saturday morning. While more than a dozen teens assaulted the driver, who struggled to defend himself, another 40 to 50 stood around the bus on Columbia Road, near the Geneva Avenue intersection, some throwing objects and taunting the driver. The driver was treated for minor injuries and released, the Globe reports today.

Transit Police asked anyone with information about the attack to contact detectives at 617-222-1050.