$33 mln pledged to prevent 'catastrophic' oil spill from Yemen oil tanker.

The United Nations has received $33 million in new pledges towards a $144 million operation to avoid an oil spill from a tanker stranded off the coast of Yemen, which threatens a major environmental disaster.

The FSO Safer, which is holding more than a million barrels of oil, has been described as a 'time bomb' because it is at risk of causing a major spill, either from leaking, breaking apart or exploding.

The commitments were made on Wednesday at a pledging conference in The Hague, co-sponsored by the UN and the Netherlands, marking the start of efforts to raise the $144 million required for the plan, according to a UN press release.

'We are grateful to the donors that committed funding today at very short notice and look forward to receiving further commitments from those that have not yet pledged. When we have the funding, the work can begin,' David Gressly, the UN Resident and Humanitarian Coordinator for Yemen, said.

The FSO Safer was constructed in 1976 as an oil tanker and converted to a floating storage and offloading (FSO) facility a decade later.

At 376 metres long, it is among the largest oil tankers in the world. The crude oil it holds is four times the amount spilled by the Exxon Valdez, the tanker that caused one of the greatest environmental disasters in the history of the United States.

The ship has been anchored off Yemen's Red Sea coast for more than 30 years.

Production, offloading, and maintenance stopped in 2015 due to the war between a pro-government Saudi-led coalition, and Houthi rebels.

The vessel is now beyond repair and at imminent risk of spilling oil, which would have far-reaching consequences.

Fishing communities on the Red Sea coast would be devastated, and the nearby ports of Hudaydah and Saleef would close. Both are critical for the entry of food, fuel and lifesaving supplies in a country where some 17 million people depend on humanitarian aid.

Any oil spill would also have an environmental impact on water, reefs and mangroves, and also disrupt shipping through the Bab al-Mandab strait to the Suez Canal. Clean-up alone would...