At least 14 people were injured after a fire broke out on a subway work train Tuesday morning in Manhattan, New York City.

Firefighters received a call just after 2:15 a.m. Eastern Time (0615 GMT) about the blaze, which sent black smoke billowing from the Astor Place station, according to authorities.

New York City Fire Department Assistant Chief Tom Currao said at a press conference that seven Metropolitan Transportation Authority workers were taken to local hospitals for smoke inhalation. Six firefighters were also injured, while another subway worker was evaluated at the scene.

As the train caught fire, a northbound train arrived at the station and discharged its passengers, Currao said. Firefighters helped them evacuate and none were injured. The fire has caused severe delays to nearby subway service.

Firefighters brought the blaze under control by 5:30 a.m. Eastern Time (0930 GMT). The cause of the fire is under investigation.