Two people are unaccounted for after a fire and explosion tore through a sawmill east of Burns Lake, B.C., on Friday, officials confirmed.

In a written statement released Saturday by the Burns Lake Native Development Corporation, the Village of Burns Lake and the Regional District of Bulkley-Nechako, officials say two people are missing "according to information from the scene of the incident." No names have been released.

In an interview with Global Television Saturday morning, Burns Lake fire chief Jim McBride said he believed they were probably dead.

Nineteen people suffered minor to serious injuries, Northern Health Authority spokesman Steve Raper told CBC News on Saturday.

Five people have been released from hospital, while seven were taken to the University Hospital of Northern B.C. Prince George. Two others were taken to hospital in Smithers, one was transported to hospital in Vanderhoof and four people with critical injuries were airlifted to hospitals in Edmonton and Vancouver.

Burns Lake RCMP responded to reports of an explosion at the mill around 8:15 p.m. PT Friday.

"The fire has since been contained, however it is still burning," RCMP spokeswoman Const. Lesley Smith said in a release. "The area has been secured and efforts continue to determine if anyone is unaccounted for."

It was a normal shift and the mill, 220 kilometres west of Prince George, was fully staffed when the blast occurred, according to police.

Workers leapt to safety

Mill worker Sam Tom told the Canadian Press workers were forced to jump from the second floor as their colleagues on the ground fought desperately to push their way in.

"I had to help a couple guys, one with a broken arm, one [with] his body severely burned," he said Saturday.

Tom said he was coming back from a coffee break when he saw a flash and heard an explosion.

"Everything just went flying," he said, struggling to describe it further.

Tom said he tried to run into the mill, but the flames were too hot.

"I couldn't even make it in there," he said. "Everything was burning."

Tom then tried to get into the mill through a blown-out wall, but debris was everywhere.

"Everybody was yelling, so [I] followed the yelling noise, then we got one guy out and more guys started coming out."

Co-workers jumped from the second-floor of the building, he said, and some people were screaming in pain.

Workers smelled gas

Frankie Erickson, a longtime employee at the mill whose sons were working during the explosion but were unhurt, said workers had smelled gas the day before.

"My neighbour smelled gas last night on his shift," Erickson, his voice breaking, told CBC News in a telephone interview. "I hear the roof literally blew off … Twenty-nine years of work in the mill, and I've never seen an explosion like this."

Erickson said his neighbour and an assistant foreman are still missing.

Smoke rises at the Burns Lake, B.C., lumber mill Saturday after it was rocked by an explosion. (Laura Blackwell/Lakes District News/Canadian Press)

"It supposed be [my neighbour's] day off but he wanted to work and he hasn't been home," said Erickson who broke down over the phone. "He's just a kid, he's just a young boy. He's just starting his life. His mum is still waiting for her son to come home."

Erickson also said workers were being pressured to work harder than ever.

"It shouldn't have happened," he said. "We averaged seven a shift and 10 hours a day and we had no coffee breaks [and] the mill ran for 20 hours straight."

Wilf Adam, chief of the Babine Lake First Nation where many workers are members, also heard anecdotal reports from workers who smelled gas.

"It was a gas explosion," said Adam. "The morning shift said that there was a big gas odour coming from the basement, and when the afternoon shift came on, that's when it happened."

'Devastating to the town'

Some injured workers who had been released from hospital gathered with their family, friends and co-workers at a community hall located on the reserve.

Adam said the facility was being used as a command centre to provide grief counselling and general updates on what was happening at the still-smoldering mill.

"We're still waiting for the fire to go out at the mill, so there will be an investigation of what happened and we'll see if we can have any closure for the two that are missing," he said.

"It's devastating to the town, it's one of our biggest employers, and our thoughts are with the people who are injured."

The mill is a joint venture with the Burns Lake Native Development Corp. and Portland, Ore.-based forest products company Hampton Affiliates.

B.C. Premier Christy Clark issued a written statement on the incident Saturday.

"Our thoughts and prayers are with those who have been injured and with their families. I join all British Columbians in praying for their speedy recovery," said the statement.

"There has been a remarkable response from across the region. I want to thank all the emergency responders, health officials and local officials for the incredible job done under very difficult circumstances.

"As officials remain on the scene, I want ... the entire community to know they have the full support of government as they go through this very difficult time."