Heavy fog was a factor in a collision involving a charter bus carrying several Warman Elementary School students on Highway 16 outside Borden, Sask., according to RCMP.

Two charter buses were en route to the ski hill when one of them was involved in a collision with a half-ton truck and a semi just before 8 a.m. The bus ended up in the median. No students or staff were injured.

The students were taken back to the Warman school on the other bus or with parents who were also driving to the ski hill, and given the option of remaining at school or going home.