A merchant vessel reported that an explosion took place near it in the Red Sea on Thursday about 19 nautical miles west of the Yemeni port city of Mokha, British security firm Ambrey said.
The vessel fit the target profile of Yemeni Houthi militants, who have attacked ships off the country's coast for several months, Ambrey said in a note.
It was en route from Europe to the United Arab Emirates and was not transmitting an Automatic Identification System signal at the time, Ambrey said. It gave no other details.
Houthis have made repeated drone and missile strikes on ships in the crucial shipping channels of the Red Sea, the Bab al-Mandab Strait and the Gulf of Aden since November.
This has forced shippers to re-route cargo to longer and more expensive journeys around southern Africa and has stoked fears that the Israel-Hamas war could spread and destabilize the Middle East.