Regina police were directing traffic at the Co-op Refinery Complex on Monday morning.
Officers blocked Ninth Avenue N. using unmarked vehicles with lights flashing and checked IDs before letting workers enter.
Meanwhile, supporters of the Unifer workers currently locked out from the reinery picketed at the corner of MacDonald Street and Ninth Avenue N.
On May 9, 2020, police said they received a complaint of people driving slow down Ninth Avenue N., a road that runs along the refinery.
CBC Saskatchewan has contacted the Regina Police Service for more information.