Two people are dead and a former employee is under arrest following a shooting at Western Forest Products sawmill in Nanaimo, B.C., early Wednesday morning.

The two deceased victims were among four who were shot at the sawmill on Wednesday. Two injured victims are being treated in hospital.

One injured victim was taken to Nanaimo General Hospital and is in stable condition, a spokesperson for Island Health confirmed to CTV News. The second injured victim is at Victoria General Hospital and is in critical but stable condition.

All four victims are male, Nanaimo RCMP Supt. Mark Fisher told reporters, but Fisher would not reveal any other details about them.

Fisher said the male suspect is 47 years old and is a former employee of the mill. Company president and CEO Don Demens would not comment on when the suspect worked at the mill or under what circumstances his employment ended.

The incident began shortly before 7 a.m. local time Wednesday, when police received multiple 911 calls for reports of shots fired at the sawmill, Fisher said.

Officers quickly arrived on the scene and arrested a male suspect 15 minutes later “without incident.”

Investigators recovered a shotgun from the scene; police said the suspect acted alone.

It appears the shooting began in the parking lot and continued in the mill’s office, Fisher said.

“My sympathies, and that of all of us at the Nanaimo RCMP, go out to the families and loved ones of all the victims,” Fisher said.

“The families and mill employees will now have to cope with the tragedy that unfolded here today, as does the community of Nanaimo. It’s going to be a challenge. But as detachment commander and a long-time resident of Vancouver Island, I can confirm that this type of extreme violence is extremely rare.”

Fisher would not speculate on a motive for the shooting. Investigators will be at the scene for days, he said.

The company has shut down all operations at its work sites on Vancouver Island out of respect for the victims, Demens said.

“Clearly we’ve had a terrible tragedy at our sawmill here in Nanaimo today,” Demens told reporters, before offering the company’s condolences to the victims’ family and friends.

“The safety and security of our employees is paramount,” he said, adding that the company will co-operate with the police investigation.

The company is also bringing in grief counsellors for mill employees, Demens said.

When asked how someone carrying a shotgun could have made his way into the facility, Demens replied that there is “standard security at the gates. I have no idea how this occurred.”

Nanaimo Mayor John Ruttan said he was "shocked" when he heard of the shooting.

"These incidents do happen, but you always hope that they won't happen in your own community," he said.

"My heart goes out to the families involved. Certainly, we're doing all we can as a community to work with the police to make sure this is investigated fully."

B.C. Premier Christy Clark also offered her condolences to the victims and their families in a statement to the legislature Wednesday.

“This kind of tragedy is almost unknown in British Columbia,” she said. “Most of us here today cannot imagine what the victims and their families must be going through.

“They should know they are not alone. The people of British Columbia are standing with them.”

With files from The Canadian Press