Highway 21 has reopened after multiple collisions this morning. 

The crashes were reported on the highway near Township Road 520 just before 7 a.m. 

Police report that heavy smoke from nearby wildfires played a role in the collisions. 

The highway was closed in both directions for a time while first responders were on the scene. Strathcona County says that the highway has since reopened. 

Two drivers were taken to hospital with non-life-threatening injuries, and the other drivers were taken by the county bus to Millennium Place in Sherwood Park.