Police are on the hunt for two suspects after 10 people were killed and 18 others were injured in a series of stabbings in Canada's Saskatchewan province.
Authorities told residents of the province to consider sheltering in place while the search was underway.
The attacks, which took place Sunday morning in James Smith Cree Nation and Weldon, involved 13 locations, with at least 15 people being treated at hospitals, officials said at a news conference. Police announced Monday that the number of injured had risen to 18.
It was possible more victims took private vehicles to seek treatment, authorities said.
"The attacks in Saskatchewan today are horrific and heartbreaking," Prime Minister Justin Trudeau tweeted Sunday evening. "I’m thinking of those who have lost a loved one and of those who were injured."
Rhonda Blackmore, the commanding officer of the Saskatchewan Royal Canadian Mounted Police, or RCMP, said it was one of the worst mass killings in the province's history, if not the worst.
"We believe some of the victims have been targeted by the suspects, and others have been attacked randomly," she said at a news conference Sunday afternoon.
Authorities named Damien Sanderson, 31, and Myles Sanderson, 30, as wanted suspects. They were believed to be traveling in a black Nissan Rogue SUV with Saskatchewan plate identification 119 MPI.
They were charged Monday and warrants were issued for their arrests, authorities said.
Myles Sanderson was charged with three counts of first-degree murder, one count of attempted murder and one count of breaking and entering at a residence. Damien Sanderson was charged with one count of first-degree murder, one count of attempted murder and one count of breaking and entering at a residence.
The RCMP believes a sighting in Saskatchewan's capital, Regina, is legitimate. The report was fielded around "lunchtime," a police official said at the news conference.
Residents were told not to approach the men but rather to call authorities immediately. Damian Sanderson is 5 feet, 7 inches and 155 pounds; Myles Sanderson is 6 feet, 1 inch and 240 pounds. Both have dark hair.
"If Damian and Myles are listening or receive this information, I would ask that they turn themselves in to police immediately," Blackmore said.
A dangerous persons alert was in effect for Saskatchewan and the neighboring provinces of Alberta and Manitoba.
"We can’t say with 100% certainty where they are right now," Blackmore said.
The RMCP and provincial authorities are investigating. A motive was not clear.
The first attack was reported at 5:40 a.m., when the RMCP's Melfort detachment was dispatched to a stabbing report, Blackmore said.
By 7:12 a.m., police had the names of two suspects, but it was not clear what led them to believe Damian Sanderson and Myles Sanderson could be the attackers. The relationship between the pair was not clear.
The Canadian Football League's Saskatchewan Roughriders said security was beefed up for Sunday's home game in Regina.
This is a developing story. Check back for updates.