Thirty workers at an offshore oil platform in Equatorial Guinea, operated by ExxonMobil have tested positive for the new coronavirus, two sources close to the ministry told Reuters, one of the largest reported clusters in the sector so far.

It highlights the risk coronavirus poses to offshore oil installations, where people typically work, sleep and eat in close quarters.

The workers on the Serpentina floating production storage and offloading platform have since been evacuated back onshore and are in quarantine, while ExxonMobil and government officials work to disinfect the platform, the sources said.

The country's largest crude stream, Zafiro, is exported by ExxonMobil primarily from the Serpentina FPSO (floating production and storage operation), which has a capacity of roughly 120,000 bpd.

A source close to the ministry said production was not impacted at Zafiro oilfield or at Jade, which has a capacity of roughly 60,000 bpd.

A spokesman for Exxon said the company's primary focus was the health and safety of its workers, but did not comment directly on the cases or share any impact on production.

Already, many countries and companies have cut the number of workers allowed at oil installations to stem the infection risk.

But the reductions have created a significant logistical challenge, particularly as plummeting oil demand hammers global prices and limits operating budgets.

In Brazil, two FPSOs were forced to shut down production after workers contracted the virus. That country's oil and gas sector has been hard hit by the virus, with 126 confirmed cases among workers, including 74 who had recently been on offshore oil platforms.

Equatorial Guinea has reported 258 confirmed cases throughout the country and one death. On Sunday, another oil major Total confirmed 14 cases at its sites in Congo Republic.

(Reporting by Libby George in Lagos and Wendell Roelf in Cape Town; additional reporting by Bate Felix in Paris; editing by Louise Heavens and Barbara Lewis)