More than 50 workers at a potash mine site west of Saskatoon were forced to spend the night underground after a piece of equipment caught fire.

The 54 workers were all able to reach underground shelters safely, said Mike Dirham, general manager at the Agrium Vanscoy mine.

Agrium's Vanscoy mine, marked on this map, is located about 30 kilometres southwest of Saskatoon. (Google Maps) By 1:30 p.m. CST Saturday, all had been brought back to the surface.

"Everybody's reported to be safe. There were no injuries. [They] just had to wait out the smoke in the mine and stay in refuge for awhile," said Dirham.

The fire broke out at around 9:45 p.m. CST on Friday, said Dirham. It was extinguished at around 5:20 a.m. CST Saturday.

Dirham said the piece of equipment had a fire suppression system, but it failed to extinguish the blaze — so the workers moved to the underground shelters.

The shelters have food, water, emergency equipment and telephones, and are equipped to handle evacuations of about 36 hours, said Dirham.

Vanscoy is about 30 kilometres southwest of Saskatoon.