Canadian police are investigating a terror attack after an officer was stabbed and four pedestrians were hit by a fleeing U-Haul truck Saturday night in Edmonton, The Globe and Mail reported. Police arrested a Somali refugee who authorities investigated in 2015 for allegedly espousing extremist ideology, though they determined that he did not pose a threat at the time. The attacker first rammed his car through traffic barricades and hit a police officer, before getting out of the car to repeatedly stab the injured officer. The man fled on foot, but police later stopped a U-Haul truck driver who matched the suspect’s description. The man then sped away and swerved into four pedestrians. The attacked officer is being treated for non-life-threatening injuries. The four pedestrians are also receiving medical care, though their conditions have not been reported. An Islamic State terror group flag was found inside the suspect’s car.