The United Nations has begun an operation to remove 1.1 million barrels of oil from a disintegrating supertanker anchored off Yemen’s Red Sea coast.

A rescue ship with a crew of experts arrived at the FSO Safer on Tuesday.

They will undertake the work of securing the transfer of the oil to another tanker, the Nautica, which is due to sail from Djibouti next month.

There is an imminent danger that the Safer could explode or disintegrate, causing an environmental disaster.

The UN has so far raised $114m (£92m) to pay for the unprecedented project through donations from dozens of member states, private companies and even the general public through a crowdfunding campaign.

But she says another $29 million is urgently needed, including mooring the Nautica safely on a rigged loading buoy and towing the Safer to the recycling yard.

He added that it was “a striking example of the importance of prevention”.

“Aside from a potential humanitarian and environmental catastrophe, the money spent now will prevent a catastrophe that could cost billions in the future.”

Safer was built as a supertanker in 1976 and later converted into a floating oil storage and offloading facility. It is moored near the Ras Issa oil port, which is under the control of the Yemeni Houthi rebel group.

Its structural integrity has deteriorated significantly since maintenance operations were suspended in 2015, when the Houthis took control of large parts of Yemen and a Saudi-led coalition intervened to support the Yemeni government. The ensuing war reportedly killed more than 150,000 people and left another 21 million in need of assistance.

The United Nations says a major spill into the Red Sea would destroy coral reefs, mangroves and other marine life, expose millions of people to highly polluted air, destroy fishing communities, and force nearby ports to close and disrupt shipping through the Suez Canal.

She estimates that the cost of the cleanup alone will be $20 billion.