A collision in an undivided portion of Highway 63, Tuesday night, has left two people dead and another in critical condition.

RCMP say the two male occupants of a small southbound vehicle were pronounced dead on scene after colliding with a northbound passenger bus around 8:15 p.m. at Mariana Lake (around 330 kiilometres north east of Edmonton).

One the of the occupants of the bus was rushed to hospital with life threatening injuries.

The 20-person shuttle bus had been carrying eight passengers who were en route to a work camp in the area. Police say a number of people on the bus were treated for less serious injuries.

Highway 63 was shut down at Mariana Lake for about eight hours as a result of the crash, reopening at 4 a.m.