Wood Buffalo RCMP said officers had shut down Highway 63 in both directions Monday afternoon, after a semi and road grader collided.

Police said the collision happened at about 2:30 p.m. about 50 kilometres south of Fort McMurray. A semi with two tankers of ammonia was involved in the collision, and police said the ammonia was leaking.

RCMP said traffic in both directions was being diverted onto Highway 881 as a result of the closure.

RCMP said later Monday afternoon that crews would open the southbound lane of the highway to traffic in both directions – the northbound lane would stay closed until further notice.

Police said crews will be directing traffic at the scene, and motorists were asked to drive carefully around the partial closure.

No one was injured in the collision, police said, and RCMP are investigating the crash.

Police asked anyone who saw the collision to contact Wood Buffalo RCMP at 780-788-4040.