The Delta Blue crude oil tanker reported a third and fourth incident in the last 24 hours off Yemen's port of Mokha, the United Kingdom Maritime Trade Operations (UKMTO) agency said on Friday.

The crew and vessel are safe and proceeding to their next port of call, the UKMTO said in an advisory note.

The latest incidents included an attack by an uncrewed surface vessel and another by a missile that landed near the ship, UKMTO said.

On Thursday the ship's captain reported that two small craft had approached and fired a rocket-propelled grenade which exploded near the Liberia-flagged Delta Blue some 45 nautical miles south of Mokha.

Each of the two small boats had four people on board, UKMTO said.

Hours later, another missile exploded close to the tanker, it said.

Athens-based Delta Tankers manages the vessel, according to LSEG data. The company did not immediately respond to a Reuters request for comment.

Yemen's Iran-aligned Houthi militants have launched attacks on international shipping in the Red Sea region since November in solidarity with Palestinians in the war between Israel and Hamas.

The attacks have drawn U.S. and British retaliatory strikes and disrupted global trade as ship owners reroute vessels away from the Red Sea and Suez Canal to sail the longer route around the southern tip of Africa.