PHILADELPHIA — Federal officials will investigate a commuter train fire in Philadelphia this week in which more than 300 passengers were safely evacuated.

The National Transportation Safety Board announced Friday that it will look into the blaze, which was reported about 6 p.m. Thursday on a Southeastern Pennsylvania Transportation Authority train on the Wilmington/Newark Line.

The fire apparently started under the first car of the six-car train and flames soon engulfed that car as SEPTA crews quickly got all the passengers to safety, the agency said.

The roughly 325 passengers aboard the train were later transferred onto shuttle buses that took them to all the train's scheduled stops. No injuries were reported.

The cause of the fire remained under investigation Friday.