HOLLIDAYSBURG, Pa. (AP) — A shooting along a rural road Friday left four people dead, including the gunman, and three state troopers injured, authorities said.

The shooting scene "extended over several miles" in Frankstown Township, about 70 miles west of Harrisburg, Blair County District Attorney Rich Consiglio said.

The dead were three men and one woman, Consiglio said. It wasn't immediately clear who killed the gunman.

The victims' identities weren't immediately released.

Three state troopers were also injured during the melee.

One trooper was shot in his bulletproof vest and escaped serious injury, a state police spokesman said.

A second trooper was struck by broken glass when his vehicle was fired on, and a third trooper was in a crash involving the gunman, Consiglio said.

The public is not at risk, Consiglio said. Nearby schools weren't placed on lockdown, township supervisor Mark Schroyer said.