Highway 599 was closed in both directions on Saturday during a police operation.
RCMP issued a release just before 1 p.m., saying the highway was closed east of Highway 36 while officers responded to an incident.
There was no ongoing threat to the public, RCMP said.
Traffic was being diverted in both directions.
As of 6 p.m., RCMP were still on scene and were expected to remain in the area for some time investigating.
No other details were given about the nature of the operation.