An elderly school bus driver is in hospital with critical injures after colliding with a minivan at an intersection in Durham Region.

Police said the bus and van collided at Highway 7 and Brock Road over the noon hour.

Both vehicles came to rest on the lawn beside a church at the intersection. The front of the bus was crumpled and the van sustained serious damage.

The 78-year-old driver of the bus was taken to Sunnybrook hospital in Toronto with critical injuries, and the two occupants of the van were taken to Markham Stouffville Hospital with minor injuries, police said.

There were no children aboard the bus at the time of the crash.

A light standard and hydro pole were also rammed during the accident, police said.

Officers aren't sure what triggered the collision. Police closed the intersection for hours to investigate.

With a report from CTV Toronto's John Musselman