The remote town of La Loche, Sask., is reeling after at least four people were killed and others injured during a school shooting.

One suspect has been arrested and a firearm was seized, according to Saskatchewan RCMP Chief Supt. Maureen Levy.

The town’s acting mayor, Kevin Janvier, told CTV News Channel the fatalities include staff and students. He also said the suspect is under the age of 21.

However, the RCMP has released few details. Initial reports indicated that five people were killed and others were injured, but RCMP later corrected the death toll to four.

Levy said she could not provide a precise number of those wounded.

“There are other injuries and they are being treated by health care professionals at this time,” Levy said.

Prime Minister Justin Trudeau spoke about the tragedy at an emergency press conference in Davos, Switzerland.

“We all grieve with and stand with the community of La Loche and the province of Saskatchewan on this terrible and tragic day,” Trudeau said.

Investigators were dispatched to the school and a second location in La Loche, RCMP said.

The incident happened around 1 p.m. at Dene High School in La Loche, a remote town of approximately 3,000 people. It is located about 600 kilometres north of Saskatoon.

A male student told CTV Saskatoon that he saw a tutor get shot inside a classroom.

“The tutor went towards the door and she got shot and I just hid under the desk and phoned 911 and helped the teacher stop the bleeding,” said the witness, who asked to remain anonymous.

A 16-year-old student told the Canadian Press that his friends ran past him yelling “There’s a shotgun!” as he returned to school from lunch break.

“And then I was hearing those shots, too, so of course I started running," he said.

A nearby elementary school was put under lockdown as a precaution, RCMP said.

Trudeau said he received regular updates from law enforcement officials and expressed gratitude to first responders.

“Obviously this is every parent’s worst nightmare,” Trudeau said.

“When I spoke with community leaders they obviously expressed that the community is reeling and all of us across this country’s hearts are going out to the family and to the whole community.”

By late Friday, community members were holding a candle-light vigil outside the school.

Community gathering to say a prayer outside of school where people were shot in la loche. pic.twitter.com/liKvMQEyrI — Sarah Plowman (@SarahPlowmanCTV) January 23, 2016

Public Safety Minister Ralph Goodale said that RCMP commissioner Bob Paulson will employ all resources necessary to conduct a thorough investigation.

“Commissioner Paulson is making absolutely sure that the La Loche detachment has everything they need to conduct a proper investigation and deal with this situation,” Goodale told CTV Regina.

Goodale added that Health Minister Jane Philpott is ensuring that health support services are provided to the isolated community.

“We’ll need to make sure they have everything they need in terms of initial supports,” Goodale said.

The Northern Lights School Division said it is working with provincial agencies to bring crisis response teams to La Loche.

“Our hearts are broken for each of the victims and their families and for all the students and staff at the La Loche Community School,” director of education Ken Ladouceur said in a statement on Facebook.

Saskatchewan Premier Brad Wall posted a statement on Facebook about “horrific events.”

Words cannot express my shock and sorrow at the horrific events today in La Loche. My thoughts and prayers are with all... Posted by Brad Wall on Friday, January 22, 2016

The community’s NDP MP and former mayor, Georgina Jolibois, said she was “shaken up” by the incident. She said her own family members were inside the school during the shooting and later confirmed that they were unharmed.

The region’s MLA described the school as a “beacon of opportunity and hope” for the area.

“I know from working with them that the school and the staff and the kids were just fantastic. This is just devastating,” Buckley Belanger, MLA for Athabasca, told CTV News Channel.

NDP Leader Tom Mulcair and interim Conservative leader Rona Ambrose expressed condolences for those affected by the shooting.

My thoughts are with those affected by the shooting at La Loche Community School and @GeorginaNDP whose family members are at the school. — Tom Mulcair (@ThomasMulcair) January 22, 2016

Shocked and saddened by the shooting in La Loche. My thoughts and prayers are with the community and those touched by this violence. — Rona Ambrose (@RonaAmbrose) January 22, 2016

News of the shooting travelled as far as Australia, where Milos Raonic dedicated his third-round win to the community of La Loche.

With files from CTV Saskatoon and the Canadian Press