BOSTON (AP) -- State police are investigating separate accidents in which motorcyclists suffered serious injuries.

A 39-year-old man is being treated for life-threatening injuries after losing control of his motorcycle on Route 128 near Route 1 in Westwood and crashing off the roadway shoulder at around 4 p.m. Monday

The man, from Stoughton, is at Massachusetts General Hospital in Boston.

In Chelsea, a 58-year-old man suffered serious injuries after losing control of his motorcycle on Route 1 near the Sixth Street ramp and crashing into a minivan at around 4:35 p.m. Monday.

Police say the Peabody man has been taken to Massachusetts General Hospital. The 35-year-old minivan driver and his 23-year-old passenger, both from East Boston, have not been injured.