Britain’s maritime agency and the security firm Ambrey have received reports of an incident on Thursday around 15 nautical miles southwest of the Yemeni port of Aden, advisory notes said, Reuters reports.
The UK Maritime Trade Operations (UKMTO) advised ships to proceed with caution and report any incident.
Yemeni Houthi militants have been attacking ships in the Red Sea since November in what they say is a campaign of solidarity with Palestinians during the Israel-Hamas conflict in Gaza.
The Houthis said on Wednesday that they had carried out three military operations in the Gulf of Aden and the Indian Ocean.