The employees made their way to a refuge chamber and were safely brought to the surface without injury about nine hours after the event.

The incident followed a 3.7 magnitude earthquake the previous morning in the northern Goldfields region.

BHP said today that mining had been temporarily suspended while experts assess the impact on operations.

Aside from a small crew working to re-establish access and carry out inspections, assessments and maintenance, underground personnel have been informed they were not required at work until further notice.

BHP didn't put a number on how many workers were affected.

The company said the other Nickel West operations, Mt Keith, Cliffs, Kalgoorlie, Kambalda and Kwinana were unaffected and were operating as normal.

“While Kwinana nickel refinery production will be maintained in the short term, the temporary suspension of the Perseverance underground operation is expected to result in a reduction of total saleable nickel production at Nickel West in the December 2013 quarter,” BHP said.

BHP said it would report any impact on production in its quarterly operational review, due out in mid-January.

The Nickel West operations produced 28,400 tonnes of nickel, its second-best quarter since September last year.

The division employs around 3000 people.

Nickel is considered a non-core commodity for BHP and there has been speculation the company may look to offload the Nickel West division.

The company is focused on iron ore, petroleum, copper and coal.

BHP shares dropped 0.7% today to $A37.75.