A Somali-born refugee has been arrested in connection with attacks in Edmonton, Alberta in which five people were injured, officials say.

The unnamed 30-year-old man is suspected of stabbing a policeman and injuring four pedestrians on Saturday.

The officer was controlling traffic at a Canadian Football League game when he was struck by a car at high speed and then attacked with a knife.

Prime Minister Justin Trudeau has called it a “terrorist attack”.

Edmonton officials say the suspect could face terror and murder-related charges. They add that he had been known to police for believing in extremist ideology.

According to broadcasters CBC and CTV, a flag belonging to so-called Islamic State was found inside the vehicle that hit the police officer.

The officer and his vehicle were rammed by a car outside Alberta’s Commonwealth Stadium on Saturday evening.

The driver then stabbed the uniformed officer several times, before fleeing on foot.