LITITZ, Pa. (AP) - State troopers opened fire and gave chase to two fleeing vehicles after one trooper was struck during a traffic stop on an interstate in Pennsylvania, police said.

Troopers tried to stop two sport utility vehicles, one black and one white, in the eastbound lanes of Interstate 76 in Elizabeth Township shortly after 11:30 p.m. Friday.

One trooper approached the black SUV and the other approached the white SUV, and the first trooper reached into the black SUV to turn off the ignition, but the driver started the vehicle and drove forward, striking the trooper, police said.

The white SUV also pulled away and both fled at high speed, police said. Police said both troopers fired their pistols, but it's unclear whether the vehicles or drivers were struck. The troopers tried to pursue the fleeing SUVs but were unable to locate them, police said.

Police said the trooper who was struck was taken to a hospital for evaluation; the extent of injuries wasn't disclosed.