Officials have not given a motivation for the shooting that also injured several people in La Loche, an impoverished community about 600 km (375 miles) north of the city of Saskatoon.
“Obviously this is every parent’s worst nightmare,” said Prime Minister Justin Trudeau, who initially reported five people were killed. He was in Davos, Switzerland, for the annual World Economic Forum.
The latest shooting occurred in the high school, called the Dene Building, and another location in Saskatchewan, Trudeau and Canadian police said.
Police took the suspect into custody outside the school and seized a gun. They have not released the identity of the suspect or victims.
Chief Bobby Cameron of the Federation of Saskatchewan Indian Nations, which represents more than 70 of the province’s Indian bands, said a few students were in surgery Friday evening in Saskatoon, the province’s largest city.
“Everyone is still in shock and disbelief,” Cameron said. “It’s a very, very horribly tragic event.”
A teacher and a teacher’s assistant were among the four killed, said Cameron after talking with community members.
La Loche acting Mayor Kevin Janvier told the Canadian Press the incident may have started at the suspect’s home.
“I’m not 100 percent sure what’s actually happened but it started at home and ended at the school,” Janvier said.
La Loche student Noel Desjarlais told the Canadian Broadcasting Corporation that he heard multiple shots fired at the school, which has about 900 students.
“I ran outside the school,” Desjarlais said. “There was lots of screaming, there was about six, seven shots before I got outside. I believe there was more shots by the time I did get out.”
A cellphone video taken by one resident and broadcast by the CBC showed students walking away from the school across the snow-covered ground and emergency personnel moving in.
Among Canada’s provinces, Saskatchewan had the highest rate of police-reported family violence in 2014, double the national rate of 243 incidents per 100,000 people, according to a Statistics Canada report on Thursday.
Extra doctors and nurses were sent to treat patients in Keewatin Yatthe Regional Health Authority’s 16-bed hospital, said spokesman Dale West. He declined to say how many people had been injured.
“It’s really sad in La Loche today, very depressing,” said Tenisha Lemaigre, who lives in the town of less than 3,000 people and said she knew many students.
Unemployment runs above 20 percent in the area but three-quarters of working-age people are classified as retired or not looking for work, according to 2011 government figures. Residents say the real unemployment rate is above 50 percent.
In 2014, a teacher expressed concern about violence at the La Loche school, noting that a student who had tried to stab her was put back in her classroom after serving his sentence, and another attacked her at her home.
“That student got 10 months,” Janice Wilson told the CBC of the student who tried to stab her in class. “And when he was released he was returned to the school and was put in my classroom.”