More than 50 workers at a Saskatchewan potash mine are safe after spending Friday night in emergency shelters because of a fire.

The fire at the Agrium facility near Vanscoy broke out on an underground loader and filled the mine with smoke.

General manager Mike Dirham says the miners headed for the shelters to escape the smoke. The shelters have food, water and telephones, and the miners don't need to wear masks when they're sealed.

Dirham says emergency personnel went into the mine and put the fire out. Once the smoke cleared the workers were escorted out uninjured.

The cause of the fire is under investigation and underground operations will remain suspended until it's considered safe to resume them.

Fires at potash mines in Saskatchewan are not uncommon, there have been at least two similar incidents in the past two years.