According to the United Kingdom Maritime Trade Operations (UKMTO), four small boats — each carrying four to five people — approached a vessel travelling some 80 nautical miles off the coast of Djibouti.

The closest small boat “paralleled the ship’s course” about a half a mile away from it before breaking off, the UKMTO said in an advisory note posted on X, dubbing the manoeuvre “suspicious”.

The note added no weapons were seen during the incident, which comes as Yemen’s Houthi rebels promised to continue attacks on any ship travelling to or from Israel in the area.