The stunning attacks, which police say took place Sunday in different 13 locations, have rattled the region. Authorities said they think the suspects targeted some of their victims and attacked others at random.

“There’s a lot of grief, there’s a lot of anxiety in our province and in our communities,” Chief Evan Bray of the Regina Police Service said Monday about one of Canada’s deadliest mass casualties.

Earlier Monday afternoon, police raised the number of injured in the violence to 18.

Prime Minister Justin Trudeau called the attacks “shocking and heart-breaking.”

“This kind of violence, or any kind of violence, has no place in our country,” Trudeau said Monday in Ottawa. “Sadly, over these past years, tragedies like these have become all too commonplace.”

The Royal Canadian Mounted Police also released arrest warrants on Monday afternoon that detailed the charges so far against the suspects.

Police said they intended to charge Myles Sanderson with three counts of first-degree murder, one count of attempted murder and breaking and entering. Damien Sanderson was facing one count of first-degree murder, as well as one count of attempted murder and breaking and entering.

Rhonda Blackmore, a commanding officer of the RCMP, said in a statement Monday that the national police force has hundreds of staffers at work on the investigation.

“To the people of Saskatchewan and beyond — please be assured that we are using every human, investigational and technological resource we have available to locate and arrest the persons responsible for this tragedy and to ensure your safety,” she said.

On Sunday, Blackmore described the attacks as “horrific” as she shared unfolding details.

At 5:40 a.m. local time Sunday, the RCMP picked up a call about a stabbing on the James Smith Cree Nation in northern Saskatchewan. Within minutes there were other calls to the Saskatchewan RCMP Divisional Operational Communications Center with news of more stabbings across the community, Blackmore said.

Blackmore, commanding officer of Saskatchewan RCMP, said police were investigating 10 deaths in 13 locations on James Smith Cree Nation and in the nearby community of Weldon, about a three-hour drive north of Regina. At least 15 more victims had been sent to hospitals, she added as she chronicled police action after the discovery of the carnage.

Ninety minutes after the first call, police issued a Dangerous Persons Alert to the James Smith Cree Nation and neighboring communities advising residents to shelter in place.

At 7:57 a.m., RCMP sent a second update with details of the suspects — an alert blasted to the province of 1.1 million people about 20 minutes later.

At 9:45 a.m., a new bulletin warned of random attacks and multiple victims.

More than six hours after news of the first stabbing, the RCMP issued one more bulletin after a report of the suspects in Regina in a black Nissan SUV. People in the capital of 226,000 were urged to take precautions and shelter in place: “DO NOT APPROACH.”

Later that day in Regina, a sold-out crowd was due at Mosaic Stadium, where the Saskatchewan Roughriders would take on the Winnipeg Blue Bombers in the Canadian Football League’s annual Labour Day Classic. The team issued a statement touting beefed-up security.

RCMP forces in neighboring provinces of Manitoba and Alberta were advised to extend the Dangerous Persons Alert to their provinces.

Chief Bobby Cameron of the Federation of Sovereign Indigenous Nations suggested Sunday that the attacks might have been drug-related.

“Our heart breaks for all those impacted,” Cameron said in a statement. “This is the destruction we face when harmful illegal drugs invade our communities.”

He added that the FSIN, which represents 74 First Nations in Saskatchewan, wanted authorities to heed demands from the chiefs, councils and their memberships to ensure safer and healthier communities.

In a video Monday, Saskatchewan Premier Scott Moe called the attacks “horrific beyond anything that any of us could ever imagine.”

Moe also warned that innocent people are in danger every moment the suspects are at large. He urged anyone with information about them to contact police.

Trudeau also announced Monday that the Canadian flag on Parliament’s Peace Tower would fly at half-staff Monday and Tuesday in memory of the victims.

News of the killings also grabbed international attention as political leaders offered their condolences.

“The brutal attacks in Saskatchewan, Canada are horrific and devastating. My thoughts are with you dear (Justin Trudeau), the victims and the bereaved,” German Chancellor Olaf Scholz wrote Monday on Twitter. “Those responsible must be brought to justice.”

EU Commission President Ursula von der Leyen said on social media that Europe mourns with the Canadian people. She added that she planned to pay tribute to the victims when she visits the Saskatchewan city of Saskatoon in two weeks.