Several passengers were injured Friday evening when a SEPTA Route 66 trolley collided with a tractor trailer in Holmesburg.

The accident happened at about 5:40 p.m. on Frankford Avenue and Welsh Road.

Andrew Busch, a SEPTA spokesman, said four passengers who were aboard the trolley reported injuries and were transported from the scene.

Fire officials said two passengers were taken to Aria-Torresdale Hospital and two were taken to Nazareth Hospital with minor injuries.

Officials were investigating the cause of the crash, and Busch said minor delays were possible in the area.

The Route 66 trolley is trackless and is powered by overhead wires, Bush said.

The trolley involved in the accident was to remain there while officials investigated the crash, and other trolleys passing the site would be able to navigate around it until the scene was cleared, Busch said.