'Risk is high': ship arrives to pump oil from Yemen tanker

A UN-owned ship arrived off war-torn Yemen on Sunday for a risky operation to pump more than a million barrels of oil from a decaying tanker and prevent a catastrophic spill.

After years of tense diplomacy between the United Nations, Yemen's Houthi rebels and the internationally recognised government, the Nautica entered Yemeni waters at midday, and was expected to moor soon alongside the FSO Safer, a rusting super-tanker in the Red Sea (pictured above).

The delicate operation to transfer 1.14 million barrels of Marib light crude to the Nautica, bought by the United Nations for the operation, is expected to begin towards the end of the coming week.

Despite stringent safety checks, concerns remain about a spill or an explosion. The Safer is carrying four times as much oil as was spilled in the 1989 Exxon Valdez disaster off Alaska.

"The risk is high. The risk is very high," said Mohammed Mudawi, the UN Development Programme (UNDP) project manager for the ship Safer.

"But we are hoping with the completion of the project that this will be eliminated."

Maintenance operations on the Safer were suspended in 2015 because of Yemen's war, and the UNDP has for years warned it could "explode at any time".

A major spill could result in ecological disaster, devastate Yemeni fishing communities, and close lifeline ports and desalination plants.

The potential spill – which could cost more than $20 billion to clean up – would possibly reach Saudi Arabia, Eritrea, Djibouti and Somalia, the UN has warned.

The Iran-backed Houthis seized Yemen's capital Sanaa in 2014 and have been fighting a Saudi-led coalition since March 2015, in a conflict that has cost hundreds of thousands of lives and left most Yemenis dependent on aid. (AFP)