Yancoal has announced over 200 employees will be stood down or re-deployed from the Austar coal mine in NSW.

The mine at Paxton, west of Cessnock, will be stripped down to a skeleton crew in line with compliance requirements.

The 100-year-old mine was the site of an incident in 2014 that killed two men, Philip Grant, 35, of Metford and 49-year-old Jamie Mitchell of Aberdare.

They were working about 10 kilometres from the mine's entry and 500 metres below ground when a wall collapsed.

All underground longwall production activities at the operation have been prohibited following two prohibition notices issued after significant coal burst events, in which coal suddenly and violently erupts into the mine.

The first Resources Regulator notice came in February 2018 when approximately 50 tonnes of coal was ejected from the face of the mine, injuring one worker.

A second notice came in May 2018 after an estimated 60 tonnes of coal was ejected, with about two tonnes landing in the walkway.

No workers were injured, but the coal burst caused significant damage to equipment.

The mine has permission for some controlled cutting under strict conditions to test additional ways to mitigate a coal burst risk.

The Resources Regulator says the notices will remain in place until detailed geotechnical assessments and comprehensive risk controls are implemented.

Yancoal Australia CEO Reinhold Schmidt said efforts are being made to move employees to other mines.

“We have worked to redeploy the majority of the Austar workforce to the Ashton, Abel and Moolarben underground mines in the interests of providing continued employment for our people,” he said.

“Until all legal avenues have been exhausted and we can re-enter the mine to move the longwall, we are unable to continue proposed longwall activity.”