Toronto police say an officer involved in the deadly shooting of a young man on a city streetcar over the weekend has been suspended.

Sammy Yatim, 18, was killed early Saturday morning following an altercation with police -- an incident that has caused public outrage.

Ontario's Special Investigations Unit is probing the incident, which was captured on video.

Chief Bill Blair says police will conduct a thorough investigation to find out how and why the young man was killed.

Toronto police spokesman Mark Pugash says the officer involved in the shooting has been suspended with pay.

A police union representative says the officer is "devastated" and overwhelmed by the magnitude of what happened.

Blair says he understands the public has many questions about police conduct after the incident was captured on video, and he says the "tragic death" is being taken very seriously.

Blair says police will co-operate fully with the province's Special Investigations Unit, which is examining Yatim's death.

The SIU says there was an "interaction" between Yatim and police in which the 18-year-old sustained multiple gunshot wounds. They say a Taser was also deployed.

Yatim was taken to hospital where he died of his injuries.

The incident has sparked outrage on Twitter at what some call unnecessary police force.

The SIU has assigned six investigators and two forensic investigators to analyse the incident. Witnesses are being interviewed and video footage is being scrutinized.

A post mortem was conducted on Yatim over the weekend.

A march has been organized for this evening that calls for justice for Yatim and an end to police violence.