A coronavirus outbreak has forced the closure of a major Papua New Guinea mine, its operator said Thursday, as the virus spreads to a remote corner of one of the Pacific's poorest nations.

Ok Tedi Mining said it had decided "to immediately suspend operations for at least 14 days" after seven cases were detected at the facility near the Indonesian border.

The copper and gold mine sits in the remote Papua New Guinea highlands, employs thousands of people and accounts for around seven percent of the country's GDP, according to company figures.

It is believed the virus was brought to the area by a mine worker arriving from the now locked-down capital Port Moresby more than 800 kilometres (500 miles) away, where authorities are struggling to contain several rapidly growing clusters.

"The employee is currently working in our operations, travelling to and from work on buses," Ok Tedi said in a statement.

"It is likely that more people have been infected, giving rise to an unacceptable risk of accelerated transmission within the Ok Tedi workforce."

The firm said it hopes to use the next 14 days to limit further transmission through extensive "contact tracing, isolation and testing".

Gold is among the extractives that make up a huge proportion of Papua New Guinea's economy
Gold is among the extractives that make up a huge proportion of Papua New Guinea's economy AFP / DAVID GRAY

The mine began operations in 1984 and, despite long-running environmental problems, remains vital to the Papua New Guinea economy, providing the government with much-needed tax revenue.

It is one of the largest mines in a sector that -- along with natural gas -- makes up around 10 percent of the government's revenue, according to the Extractive Industries Transparency Initiative, a watchdog group.

In 2018, extractives accounted for 89 percent of Papua New Guinea's total exports by value and a third of total GDP.

The mine's closure came as Papua New Guinea authorities reported a record 39 new virus cases Thursday, bringing the total to 153.

Until recently the country had been spared a serious coronavirus outbreak. Almost all cases have been detected in the last few weeks.

Experts fear low levels of testing mean significant numbers of cases could go unnoticed.

Many test samples have to be sent to Singapore or Australia to be confirmed.

With the capital in lockdown and the country's only designated isolation ward almost full, two sports facilities have been earmarked to become makeshift virus wards.