All eastbound lanes of a major Ontario highway were closed about 100 kilometres east of Toronto for much of Friday afternoon after snow blowing off Lake Ontario resulted in numerous collisions.

Ontario Provincial Police say at least five people were injured in multiple collisions involving nearly 40 vehicles near Brighton, Ont., 160 kilometres east of Toronto.

Police say all of the eastbound lanes of Highway 401 were closed as they investigated the accidents, including one in which 15 to 20 vehicles collided, jackknifed or went off the road.

All eastbound lanes of the highway at Port Hope, Ont. — 100 kilometres east of Toronto — remained closed Friday evening due to a serious collision in which at least one person was injured.

The slew of accidents near Brighton occurred during a snowstorm that hit the area just before noon.