An inbound commuter train plowed into a truck carrying construction equipment that was stuck at a railroad crossing in Franklin on Monday morning, injuring up to 20 people, a transit authority spokesman said.

The injured, all reported from the train that subsequently derailed, were taken to local hospitals, according to Joe Pesaturo, a spokesman for the Massachusetts Bay Transportation Authority. He said he had no condition reports, but "none of the injuries have been described as critical or serious."

The construction equipment with a bucket attached was on a low, flatbed truck. The truck driver had left his vehicle and was walking up the tracks in an effort to warn the oncoming train bound for Boston, Pesaturo said.

The train engineer saw the truck driver waving, but was unable to stop in time. When the train engine struck the truck shortly before 8 a.m., the construction equipment swung around and slammed into the first coach of the train.

Pesaturo said it was not known why the truck was stuck on the rails of the Fisher Street crossing.

He said none of the train crew was reported injured.