Two vehicles hit and killed a buffalo, the animal, Tuesday morning on the QEW near Lyons Creek Road in Niagara Falls, just about 25 kilometres from Buffalo, the city.
The people in the vehicles sustained minor injuries, police said.
Two other buffalo are still on the loose, Sgt. Kerry Schmidt said.
The large animals appear to have escaped from a local farm, police said.
Drivers in the area are being advised to use caution while the buffalo are still on the loose.
Agencies/Canadajournal