Four people are dead and two others are in hospital with serious injuries after a seven-vehicle collision on Highway 401 east of Kingston early Thursday.

The crash happened at around 1:30 a.m. and involved four tractor-trailers, a commercial truck and two cars.  

The OPP say one of the cars became fully engulfed in flames and all four people in that car were pronounced dead at the scene. 

Westbound Highway 401 was closed west of the exit for Joyceville Road as police investigate but reopened shortly after 7 p.m.

Toronto - Kingston fatal crash

The four people who died in Thursday's crash were in one car that became engulfed in flames after a collision. (CBC)

Police say the victims will not be identified until relatives are notified. There was no immediate word on the cause of the crash.