7 people suffer minor injuries, after the MBTA Green Line subway train derails near the Kenmore Station in Boston.

The first car of an MBTA Green Line train crashed into the tunnel wall after derailing just west of Kenmore Station this afternoon. Seven people suffered minor injuries, and the tracks in the area are to be closed for the rest of the day, authorities said.

The derailment happened between the Kenmore and Fenway stations, fire department officials said in a tweet.

Boston EMS spokesman Nick Martin said the seven injured would be transported to the hospital shortly. Many of the injured reported back pain, he said.

Some people were hurt when a train had to slam on its brakes to avoid rear-ending the train that derailed, the fire department said.

Passengers were escorted out of the tunnel shortly after the accident, which was reported about 12:20 p.m., MBTA spokesman Joe Pesaturo said.

The derailed car was the first of a two-car D Line train bound for Riverside. It veered from the tracks in an area where the D Line and C Line intersect, said Pesaturo.

The car is now leaning against the tunnel wall, between Kenmore and the portal on Beacon Street, said Pesaturo.

Buses will replace C Line trains from Kenmore to St. Marys Street Station and the D Line trains from Kenmore to Fenway for the rest of the day, Transit Police said.

The cause of the accident is under investigation, said Pesaturo.