A fire on an MBTA Orange Line sent hundreds running for safety and smoke boiling into the sky during the morning commute Thursday.

The fire started in at around 6:45 a.m. as the train was approaching Assembly Station, the MBTA said in a statement. Photos posted online by passengers show the fire was contained to the forward wheel area of the first car.

About 200 people were evacuated off the train by MBTA personnel, including some who jumped through broken windows and one woman who jumped into the river. No injuries were reported. 

Power was turned off between Wellington and Assembly and the Somerville and Medford Fire Departments responded, the MBTA said. It’s unclear whether the third rail was turned off by the time passengers started jumping out windows. During emergencies, signs posted in Orange Line trains say to wait for crew member instructions and to use doors at the rear of each train car as emergency exits.

According to Boston 25, in a video recorded by one of the passengers on the train, you can see passengers running along the train tracks to get away from the fire.

The MBTA said that shuttle buses replaced service between Oak Grove and Community College for about four hours. Regular service on the Orange Line resumed shortly after 10:30 a.m. 

The train has now been brought to the Wellington rail yard for an investigation, the T said, where it and the tracks where the fire occurred will be inspected. The T said it has notified The Federal Transit Administration and the National Transportation Safety Board of the incident.