An extensive manhunt in Canada has been extended into a third day, as hundreds of officers chase down the surviving suspect in a mass killing.

Myles Sanderson, a 30-year-old convicted criminal, remained on the loose, armed, dangerous and possibly injured, police said.

His brother Damien Sanderson, 31, was found dead in a grassy area of the James Smith Cree Nation in Saskatchewan, the indigenous community where most of the victims lived.

The brothers are suspected of killing ten people and wounding 18 in one of the deadliest attacks in the country's modern history.

Damien Sanderson (L) was found dead; the hunt for Myles Sanderson is in its third day
(Pic: RCMP handout)

Police said some of the victims appeared to have been targeted, while others were apparently random.

Some First Nation leaders have linked the killings to drug use, but police have not identified drugs or alcohol as a factor.

The stabbings have caused "immeasurable stress and panic" in the community, leaders from a group of 74 First Nations in Saskatchewan said.

They pleaded for members of the public to come forward with any relevant information.

Myles Sanderson has been wanted since May, when he stopped meeting his parole officer after serving a sentence for assault, robbery, mischief and uttering threats, the national broadcaster in Canada, CBC News, reported.

Citing Parole Board of Canada documents, it said that he had amassed 59 convictions.

Police said they were investigating whether Sanderson may have also killed his brother, and could have sustained injuries that might cause him to seek medical attention.

There were few details about the victims, which included men and women spanning a wide range of ages.

People from the area said a mother of two, a 77-year-old widower and a first responder were among the victims.