Ontario Provincial Police are investigating another incident of rock-throwing on a highway in Markham where a GO bus was hit.
It occurred on the evening of Nov. 30 while the bus was travelling on Highway 48 near Major Mackenzie Drive.
Photo shared by police shows the windshield of the bus cracked as a result of the impact. No one on the bus was injured.
Before the incident, there had been 20 cases of rocks being intentionally thrown at vehicles in Markham since September, with 11 happening along Highway 48.
One of the incidents caused a serious collision that left two people with life-threatening injuries. Police said one victim remains in hospital in critical condition.
Police have not released any description of the people responsible but said a light-coloured SUV may be involved.
Investigators are asking anyone with information to contact them at 1-888-310-1122, opp.rock.throwing.tips@oppca or Crime Stoppers anonymously at 1-800-222-TIPS (8477).