WARREN COUNTY, Pa. (EYT) — Warren-based State Police say two Marienville motorcyclists were involved in an accident on South Main Street, 82 feet south of Pickering Street, in Sheffield Township, Warren County.

According to police, 50-year-old Gregory W. Bloom and 55-year-old David E. Frost, both of Marienville, were traveling south on State Route 666 on motorcycles, along with two other motorcycles.

A 2004 BMW GS-1150 operated by Frost, in the front, slowed suddenly and was struck in the rear end by a 2001 Harley-Davidson DYNA operated by Bloom, police say.

Both motorcyclists lost control of their vehicles, subsequently laying them down on the roadway.

Both operators suffered moderate head injuries and were transported to Warren General Hospital by Emergycare Ambulance for further evaluation and treatment.

Neither operator was using a motorcycle helmet.

The Harley-Davidson sustained moderate but functional body damage, and the BMW sustained minor body damage.

Both motorcycles were removed from the scene by a private party.

Police say citations will be filed on Bloom for numerous traffic violations through District Court 37-2-01.