Northern Star evacuated all workers from the underground mine and deployed the site’s seismic response action plan, according to Western Australia’s Department of Mines, Industry Regulation and Safety (DMIRS).

A ground fall was located but no employees were working in the area at the time.

The mines department also stated that all affected areas had been isolated pending a geotechnical inspection.

“The mine operator will advise the department of the outcome of its investigation,” a spokesperson for the DMIRS said.

“DMIRS continues to work with Kanowna Belle’s site operations team and safety inspectors will visit the mine this week to follow up.”

The Kanowna Belle mine is around 18 kilometres north east of Kalgoorlie. It was acquired from Barrick Gold in 2014.

Northern Star employs around 1230 people across three mining areas at the Kalgoorlie operations, which include Kanowna Belle, South Kalgoorlie operations and the greater Kundana area.

The Kanowna tenement package surrounding the mine spans across 223 square kilometres of tenure.