Two children have been injured in a collision on Highway 401 in Ajax Friday afternoon.

Emergency crews were called to the eastbound lanes of the highway near Westney Road shortly after 5:30 p.m.

Ontario Provincial Police said multiple people have been injured, including two children.

They were transported to SickKids hospital in serious condition, the OPP said.

The cause of the crash is under investigation.

Several eastbound lanes of the highway are blocked due to the collision.