RICHMOND -- Two motorcyclists were airlifted to hospitals after separate crashes within a few minutes on interstates 80 and 580 in West Contra Costa County, authorities said.

A 21-year-old man was airlifted in critical condition to John Muir Medical Center in Walnut Creek after his motorcycle crashed about 7:50 a.m. on eastbound I-80 just west of Hilltop Road, according to Richmond Fire Battalion Chief Merlin Turner.

Traffic was briefly stopped on the freeway when the medical helicopter touched down to pick up the injured rider.

Another motorcyclist, who was not immediately identified, was also being airlifted to a hospital after a collision about 7:52 a.m. on westbound I-580 near the toll plaza for the Richmond-San Rafael Bridge, according to the California Highway Patrol. That person's condition was not immediately known.

A third motorcycle crash was reported about 8:44 a.m. on westbound I-80 near the Willow Avenue exit in Pinole. Responding firefighters reported that the rider suffered only minor injuries.

Check back for updates.