The Saudi-led coalition fighting in Yemen received a distress signal from an oil tanker after it was subjected to "armed harassment" off Yemen's Hodeida port, Saudi state media has reported, citing the coalition.

The report, on Wednesday, gave no further details but said there were "high-risk indicators" in waters off Hodeida port on the Red Sea, one of the world's busiest maritime lanes.

Earlier on Wednesday, the United Kingdom Maritime Trade Operations (UKMTO), part of Britain's Royal Navy, issued an advisory that a vessel near Salif port, north of Hodeida, reported a suspicious approach by an unknown craft.

UKMTO said the vessel and crew were safe and had continued their passage. It was not immediately clear if it was referring to the same incident.

Hodeida and Salif are controlled by Yemen's Iran-aligned Houthi movement, which on Sunday hijacked a United Arab Emirates-flagged cargo vessel that the group said was engaged in "hostile acts", but which the military alliance led by Riyadh said was carrying hospital equipment.

Air and sea access to Houthi-held areas is controlled by the Saudi-led coalition that intervened in Yemen in early 2015 after the movement ousted the internationally recognised government from the capital Sanaa.

The Houthis said on Wednesday that the coalition had diverted to a Saudi port a fifth fuel vessel heading for Hodeida, part of a tussle over imports into Yemen.

-Agencies

 -File photo