A man has been killed after being hit with a bolt from a crossbow in Toronto, Canadian officials say.

The victim, estimated to be in his 30s or 40s, was shot in the back outside a library in the city's east end. He was pronounced dead at the scene.

Police later arrested a man who was reportedly seen running with a crossbow and trying to escape in a van.

The motive for the attack - which happened at about 1630 local time (2130 GMT) - was not immediately clear.

Officials say there were many witnesses who could help in the ongoing investigation.