File Photo: General Cargo Minervagracht. Photo courtesy of Marine Traffic.
"Military authorities report that a vessel has been hit by an unknown projectile. The vessel is reported to be on fire," the United Kingdom Maritime Trade Operations (UKMTO) said.
In a warning on the incident, the British Royal Navy-run agency said the attack had occurred 128 miles southwest of Aden in Yemen.
No group has claimed responsibility for the attack, but Yemen's Houthi rebels have repeatedly targeted vessels in the busy shipping lanes of the Red Sea and the Gulf of Aden.
The Yemeni group, which holds swathes of territory including the capital Sanaa, has said the attacks on commercial shipping are in support of Palestinians during the Israeli war on Gaza.
The private security firm Ambrey said "a Netherlands-flagged general cargo ship reportedly came under attack", adding that there had been reports of "smoke in the vicinity of the vessel".
The Houthis have also launched frequent missile and drone attacks on Israel, which has retaliated with strikes in Yemen.
Israeli strikes on Sanaa killed at least nine people on Thursday, a day after the rebels launched a drone attack on southern Israel.
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