CLIFTON — Police say two people have died in a motorcycle crash in Clifton.

Penobscot County Chief Deputy Troy Morton says a man and a woman were killed when their motorcycle struck a guard rail on Route 9 eastbound at about 6 p.m. Sunday. He says speed appears to be a factor.

No names were immediately released.

Morton says a witness reported that the motorcycle was speeding and passing other vehicles when it lost control on a curve, went into the oncoming lane, and struck the guard rail. Both riders were thrown and pronounced dead at the scene.

Neither victim was wearing a helmet.

The accident remains under investigation.