Two people have been killed in an underground explosion at a mine in the Australian state of New South Wales (NSW), the first such incident of its kind since 2015.

Emergency services were called to the Endeavor mine at Cobar, about 700km (435 miles) northwest of Sydney, in the early hours of Tuesday after reports two people had been critically injured.

Police said a man, in his 60s, was confirmed dead at the scene and two women, both in their 20s, were brought to the surface, but one later died. The second woman was airlifted to hospital for minor injuries and shock.

Polymetals Resources, which bought the Endeavour mine in 2023, said all operations at the site had been temporarily suspended.

It did not say what caused the explosion. The company’s executive chairman Dave Sproule said it was “shocked and saddened by the tragic incident” and “our deepest thoughts and condolences go out to the employee’s families, friends and colleagues”.

Fatalities from mine explosions are rare in Australia, with the most recent death happening in 2015 at a mine in Queensland.

Cobar Mayor Jarrod Marsden said it was an “absolutely tragic” situation.

“The most valuable thing to come out of a mine are the miners, and two families don’t get to see their loved ones anymore,” he told the Australian Broadcasting Corporation (ABC).

“Cobar is a small mining community, it’s very tight-knit, and I’m sure everyone’s going to be thinking of their families today.”

A report will be prepared for the coroner and an investigation into the incident will be carried out by the state’s workplace safety authority.

According to the Endeavour mine’s website, it had been operating continuously from 1982 to 2020 and the new owners were in the process of restarting mining activities for silver, zinc and lead metal production this year.

The mine includes a 7km (4.3 miles) decline and 300m shaft, the site said.

NSW Premier Chris Minns extended his condolences to the family, friends and colleagues of the workers who died.

“This is a heartbreaking day for the Cobar community and will be felt across the entire mining industry,” he said.

Safety protocols and procedures have “greatly improved in mining”, Minns said, but the two deaths were a “sobering reminder of why we need to always remain vigilant to protect workers”.