PHILADELPHIA (CBS) – Several SEPTA trains were briefly stopped Tuesday after reports of smoke on a train at the 15th Street Station.

Firefighters were called to 15th and Market Streets, around 12:30 p.m.

No word on what may have caused the smoke but SEPTA did stop trains for about 30 minutes due to “equipment issues.”

SEPTA says trains in both directions on the Market/Frankford Line may experience delays of up to 30 minutes.

All trolleys are on diversion to 40th and Market Streets due to the incident.

There were no reported injuries.