A man fatally shot a woman decorating for a children's Christmas party at a church hall and killed two men elsewhere in a Pennsylvania township on Friday before he was shot dead in a gunfight with state troopers.

Three troopers in patrol cars were injured in a pursuit that began after the gunman, driving a pick-up truck, fired at them, police said. One trooper injured a wrist and was hit in the chest but was saved by a bulletproof vest. The gunman died during a final exchange of gunfire after ramming his truck head-on into another police cruiser.

The shootings began in Frankstown township about 9am (local time), and investigators were processing five crime scenes within about a 2.4km radius, authorities said. Troopers were responding to an emergency call of a shooting in the township when they heard calls reporting at least one other shooting elsewhere, state police said.

"It's going to take us some time to put this all together ... and know exactly what occurred," said Lt Col George Bivens, deputy state police commissioner.


Blair County District Attorney Rich Consiglio said the gunman and the victims weren't related, though the victims might have been, at least distantly.

Besides the trooper wounded twice, a second trooper was injured by glass fragments in his eye and bullet fragments that hit him in the forehead.

A third trooper sustained minor injuries from the head-on crash.

= AP