An oil tanker is on fire off the coast of Yemen after a missile strike claimed by the Houthis.
Multinational firm Trafigura, which has offices in London, said the safety of crew on the Marlin Luanda, a vessel operated on its behalf, is its “foremost priority”.
Military ships in the region are on the way to provide assistance, it said.
UK Maritime Trade Operations (UKMTO) reported an incident 60 nautical miles south-east of Aden on Friday.
It comes after an earlier incident in which two missiles were reported to have exploded in the water and “vessel and crew are safe and no damage reported”.
The Yemeni armed forces claimed it had targeted Marlin Luanda, which it described as a British oil tanker, in the Gulf of Aden.
Shipping data suggests the vessel sails under the flag of the Marshall Islands.
UKMTO said authorities have been informed and are responding to the latest strike, warning other vessels to transit with caution and report any suspicious activity.
The Houthis have repeatedly launched attacks on ships in the Red Sea since November over Israel’s war on Hamas in the Gaza Strip.
But they have frequently targeted vessels with tenuous or no clear links to Israel, endangering shipping on a key route for global trade.
Alongside numerous air strikes on key Houthi targets, the UK and US are also targeting key figures in the Iran-backed militant group with sanctions.
A second series of UK and US air strikes, carried out at the start of the week, appears to have done little to deter Houthi action.
A Trafigura spokesperson said in a statement: “Earlier on 26th January, the Marlin Luanda, a petroleum products tanker vessel operated on behalf of Trafigura, was struck by a missile as it transited the Red Sea.
“Firefighting equipment on board is being deployed to suppress and control the fire caused in one cargo tank on the starboard side. The safety of the crew is our foremost priority.
“We remain in contact with the vessel and are monitoring the situation carefully. Military ships in the region are underway to provide assistance.”
Earlier on Friday, a spokeswoman for the Prime Minister said: “We continue to call on (the Houthis) to step back from such action. We’re clear that this is illegal and unacceptable.”
Foreign Secretary Lord Cameron is currently finishing a trip to the Middle East in a diplomatic bid to reduce tensions as the Israeli bombardment of Gaza continues.