The mother of a 17-year-old who died after being Tasered by Winnipeg police says the device should be banned.

Police say the Metis teenager was armed with a knife when they confronted him in an alleyway, and refused to give up his weapon.

Investigators are still looking into how Michael Langan died and autopsy results are pending. But Langan's mother, Sharon Shymko, said she believes he died from the Taser shock.

"He is gone. And he is gone because of that machine," she told CTV News.

The incident occurred shortly before 3:50 p.m. Tuesday when two citizens alleged they saw the youth take property from a vehicle.

The citizens followed the boy and flagged down two uniformed police officers, according to Const. Jacqueline Chaput.

She said officers warned Langan to drop his knife several times before they used the electronic stun gun.

An ambulance was called immediately. The boy was taken to hospital in critical condition and later died.

Chaput did not say how long it took from the time that the boy was hit with the Taser until he reached the hospital, other than it was "quick."

The incident marks the first fatality following the use of a Taser by a member of the Winnipeg Police Service.

Police did not disclose any information on the officers involved other than they are on administrative leave, which is following normal protocol.

Const. Adam Cheadle, who trains Winnipeg officers on how to properly use Tasers, said the devices are on the same "playing field" as batons and pepper spray.

"It's another less-than-lethal option for them to utilize," he said.

With a report by CTV's Murray Oliver