Canadian police have launched a huge manhunt for two men suspected of stabbing at least 10 people to death in a rampage that has shocked the nation.
Two suspects named as Damien Sanderson and Myles Sanderson are on the run and considered armed and dangerous.
Victims were found in 13 locations in the remote indigenous community James Smith Cree Nation and nearby Weldon.
It is one of the deadliest acts of mass violence Canada has seen. PM Justin Trudeau said it was "heartbreaking".
At least 15 others were injured in the killing spree, with police urging residents to be extremely vigilant as they conduct a search across one of Canada's largest and most remote regions.
"I am shocked and devastated by the horrific attacks today," Mr Trudeau said in a statement. "Those responsible for today's abhorrent attacks must be fully brought to justice."
As news of the stabbings broke, a dangerous person alert was sent to all mobile phones across the provinces of Saskatchewan, Manitoba and Alberta - an enormous region almost half the size of Europe.
A state of emergency was declared in the James Smith Cree Nation - a community of about 2,000 residents north-east of the village of Weldon, which is home to just 200 people.
"Do not leave a secure location. Use caution allowing others into your residence," Saskatchewan Royal Canadian Mounted Police (RCMP) warned people across the area.
Numerous checkpoints have been set up and drivers have been urged not to pick up hitchhikers.
Rhonda Blackmore, Commanding Officer for Saskatchewan RCMP said that some people may have been targeted, while others are believed to have been "attacked randomly".
The suspects were last seen by members of the public in Regina at about lunchtime on Sunday, and may be travelling in a black Nissan Rogue, Officer Blackmore said.
The relationship between Damien Sanderson, 31, and Myles Sanderson, 30, is unclear, and the authorities have so far provided no further details.
But in May, Saskatchewan Crime Stoppers issued a wanted poster for Myles Sanderson accusing him of being "unlawfully at large" in the region.
At a news briefing on Sunday evening, police said there could be more injured people than the 15 they already knew about, who had taken themselves to hospital.
Police refused to speculate on the motive behind the attack, but Chief Bobby Cameron of the Federation of Sovereign Indigenous Nations suggested that they could be drug related.
"This is the destruction we face when harmful illegal drugs invade our communities, and we demand all authorities to take direction from the Chiefs and Councils and their membership to create safer and healthier communities for our people," Mr Cameron said.
The first emergency call was made to police at 05:40 local time on Sunday morning in the provincial capital Regina, about 280km (173 miles) south of Weldon.
This was quickly followed by many more calls for help, developing into what police described as a "rapidly unfolding event".
Anne Lindemann, a spokesperson for the Saskatchewan Health Authority, told local media that additional staff had been called in to deal with an "influx of casualties".
"They are considered armed and dangerous... If you see the suspects or their vehicle, do not approach them, immediately leave the area and call 911."
Logan Stein, a local journalist, told the BBC that the region was extremely remote. He said that the attackers appeared to have gone door-to-door attacking locals.
Chakastaypasin Chief Calvin Sanderson - one of the elected leaders that head up the region- told the Regina Leader Post that everyone in the community had been affected.
"They were our relatives, friends. Mostly we're all related here, so it's pretty hard," Mr Sanderson said. "It's pretty horrific."
Weldon resident Diane Shier said her neighbour, a man who lived with his grandson, was killed, the Globe and Mail newspaper reported.
He was described by another resident, Robert Rush, as a gentle, widowed man in his 70s.
"He wouldn't hurt a fly," Mr Rush was quoted as saying.
Another victim has been named as mother of two Lana Head. Her former partner Michael Brett Burns told local media that he was "hurt for all this loss".
Canada's Indigenous Relations Minister Marc Miller said he had reached out to community leaders to "offer Canada's full support and any assistance that will be needed in the coming days".
Timeline of events
05:40 - local time on 4 September (11:40 GMT) - police receive the first call about a stabbing in the James Smith Cree Nation. More calls start coming in within minutes
07:12 - police tell the public to seek immediate shelter and issue a Dangerous Persons Alert
07:57 - police reveal the names, descriptions and pictures of the two suspects
08:20 - the Dangerous Persons Alert is extended to the whole Saskatchewan province
11:25 - the search for the suspects is further widened to the neighbouring provinces of Manitoba and Alberta
12:07 - police alert the public that the suspect vehicle had been spotted in Regina, the provincial capital