The Ontario Provincial Police is investigating after a school bus and a horse drawn carriage collided in Arran-Elderslie.

It happened shortly after 4 p.m. Thursday on Concession 10 and Sideroad 5.

Police say all five passengers in the buggy were injured. One person was taken to hospital via air ambulance while another was transported by land ambulance. Both victims suffered life threatening injuries. The other three passengers were also taken to a nearby hospital with unknown injuries.

Police say there were students on the school bus when the crash happened but they were not hurt. The bus driver was brought to hospital for a medical assessment.

Members from the West Region OPP Technical Traffic Collision Investigation Team have been called in to assist with the investigation.

No charges have been laid at this time.

Anyone with information that could help police with the investigation is asked to contact OPP at 1-888-310-1122.