Miners who spent some 24 hours trapped underground at PotashCorp's Allan mine east of Saskatoon have made their way to the surface, after a fire forced dozens of workers to seek shelter in safety stations on Wednesday.

Around 8:30 p.m. CST Thursday, the last three workers who were in safe spaces below ground were up and out. Earlier in the day, 51 of their co-workers returned to the surface.

A union leader said he was able to speak to some of the workers who were brought up and reported they were safe, but some were "grouchy and hungry".

Mike Belyk was one of the workers who returned to the surface Thursday afternoon.

"[I'm] just relieved to be back up, to get home see your family," he said. "Other than that it wasn't too, too bad."

Belyk said miners were in contact with rescue teams and people found ways to pass the time.

"We had communication. Played cards. Played a lot of cards."

General manager of the Allan mine, Larry Long, said crews had to restore power to fans that shorted out in the fire so air could circulate, clearing smoke and fumes. (CBC)

He added some of the workers were even able to sleep for a bit.

According to PotashCorp the workers were stuck in the east wing of the mine.

Larry Long, general manager of the mine, said they were safe and there were no reports of injuries.

"[It's] just a matter now, [of] waiting for the smoke and gases to clear," Long said. "As they clear past the refuge stations, we'll bring the people out, bring them to surface."

Power systems that had been down were also restored, Long said, allowing rescue crews to get more fans going to clear the smoke and gas.

Power and phone communication were knocked out at the mine in the incident, but PotashCorp said mine safety workers and oxygen masks were able to reach the trapped workers.

A PotashCorp spokesperson said the fire broke out in a water truck deep underground around 4 p.m. Wednesday. That forced 96 workers to make their way to refuge stations throughout the mine.

Some of the workers also used a specialized safety device, a large plastic sheet called a brattice, to seal themselves off in safe portions of mine tunnels.

Dozens of miners were trapped overnight following a fire Wednesday afternoon at the Allan potash mine east of Saskatoon. (CBC)

Some miners returned to the surface overnight, beginning around 11 p.m. Wednesday. On Thursday morning, 54 were still waiting for the all-clear signal.

Whenever there is a fire, strict safety protocols dictate that miners must make their way to refuge stations underground, to ensure they are safe from the flames and have fresh air.

While no one was hurt, smoke from the fire was lingering in parts of the potash mine because the fire knocked out a couple of the fans used for circulating air underground.

"They're just being extra cautious in terms of waiting for the smoke to dissipate," Bill Johnson, a spokesman for PotashCorp, said Thursday.

Cards and water in safe rooms

He added the safety units are equipped to keep workers safe and comfortable.

"There's food and there's water. They're not palatial but they're sealed off, they've got cards to keep occupied."

Ron St. Pierre, president of United Steel Workers local for the mine, told CBC News that workers can remain in the safe areas for long periods of time.

"They're sealed in," he said. "They'd be able to stay there … a long time."

St. Pierre noted the mine has an alarm system that quickly gets the attention of workers.

Ron St. Pierre, president of the union local for mine workers at the Allan site, said workers can remain underground in safe areas for extended periods of time. (CBC)

There have been similar occurrences at other Saskatchewan mines in recent years.

In February, about 50 workers at the Agrium mine near Vanscoy, Sask., spent a night in the facility's refuge station due to a fire.

In 2013, 318 miners raced to safety units after flames broke out at Mosaic's K2 potash mine near Esterhazy. They spent several hours underground until the smoke had cleared. Seven years earlier, a fire at the same facility trapped 72 workers in refuge stations for 30 hours.

Another fire in 2012 at PotashCorp's Rocanville mine in eastern Saskatchewan forced 20 miners to seek shelter. It took about 10 hours to put out the fire and several more hours for rescue crews to determine that it was safe for workers to leave.

According to Johnson, the Allan mine will remain closed as company officials investigate.