Authorities say at least nine people died in a series of crashes apparently caused by heavy smoke and fog overnight on Interstate 75 in north Florida.

Florida Highway Patrol Lt. Patrick Riordan says the pileups happened around 3:45 a.m. Sunday on both sides of I-75 south of Gainesville. All lanes of the interstate are still closed.

He says several people were also injured and taken to Gainesville hospitals. Their conditions were unclear.

Riordan says FHP had closed the highway briefly overnight because of the mixture of smoke and fog in the Paynes Prairie area. It was reopened shortly before the crashes occurred.

The crashes involved four to five large commercial vehicles and at least six passenger vehicles.

Riordan says U.S. 441 is also closed and traffic is being diverted onto U.S. 301 and State Road 27.