NEWARK, Del. - As many as 20 million swarming bees released after a tractor-trailer hauling them overturned near Newark Tuesday have shut down a highway ramp and kept investigators from getting near the vehicle, said Delaware State Police, who urged drivers to stay away from the area.

The tractor-trailer fell on its side about 6:10 p.m. on a curve on a ramp from Route 896 to Interstate 95, said state police spokesman Sgt. Paul Shavack.

The rig, travelling from Florida to Maine, carried 460 crated hives, or an estimated 16 million to 20 million honeybees.

The driver and two passengers were able to get out of the vehicle, but were stung 50 to 100 times each, troopers said. They also suffered minor injuries in the crash and were taken to Christiana Hospital.

Shavack said there were reports of passers-by being stung.

State police have had an official honeybee swarm removal plan for 14 years and this is the first time they used it, Shavack said.