Hail and sleet may have been factors in a two-vehicle crash that killed three people in southern Alberta, police say.

A passenger van heading north collided with a southbound truck at about 9 a.m. Sunday on Highway 22 in the Crowsnest Pass region, police said.

All three occupants of the van were killed. They have been identified as Darrel Johnston, 52, of Crowsnest Pass and William Desjardins, 60, and James Hutchinson, 46, both of Fernie, B.C.

The two men in the truck were taken to hospital with injuries that were not life-threatening.

The cause of the crash has not been determined, but road conditions were poor, police said.

Hail, sleet and wet snow were falling, and the temperature was hovering just above 0 C. Other drivers reported that the road was covered with ice and slush.