At least three people are dead and 14 injured after a crash involving a Greyhound bus and three other vehicles early Wednesday in southern Illinois, a release from state police said.

"Initial investigation indicates a Greyhound passenger bus with passengers was traveling westbound on Interstate 70 and struck three commercial motor vehicles parked on the exit ramp to the Silver Lake Interstate 70 westbound rest area," the release said.

No one in the other vehicles was injured, the statement said.

The crash happened just before 2 a.m. in Madison County.

"Three fatalities are confirmed and multiple others were taken to a hospital with serious injuries, four by helicopter and at least 10 by ambulance,'" the statement said.