Six people were injured at a Free Methodist church camp Saturday evening when a woman accidentally backed her car into a crowd.

Two children were transported by medical helicopter to UPMC Children's Hospital in Pittsburgh.

Liverpool Township Fire Chief Mike Bahen said some 400 members of Free Methodist churches from across the region were attending the annual "camp meeting" this weekend when the accident occurred at the Tri-State Free Methodist Campground in Liverpool Township, Ohio, just about 20 miles west of Aliquippa and immediately outside the city of East Liverpool, Ohio.

Mr. Bahen said a woman had parked her car in a field near the mess hall and was attempting to move the vehicle when it backed over six people.

"We don't know if the pedal got stuck or if she was meaning to go forward and went backward but we know it was an accident,'' the fire chief said. The woman has not been identified and she was taken to a local hospital for evaluation.

Mr. Bahen said of the six people who were struck by the vehicle, four were children. Two of the children, a girl who is 7 or 8 years old and and a boy who is 3 or 4 years old, according to the fire chief, were seriously hurt and flown to Pittsburgh. The remaining injured people were taken to a local hospital for treatment. Mr. Bahen did not know their conditions.

The accident occurred between 5:15 p.m. and 5:30 p.m. Saturday.