Two vessels came under attack on Monday in the Red Sea off Yemen's port city of Hodeidah, with one ship reporting it had sustained some damage, Britain's maritime agency said.
A vessel 97 nautical miles northwest of Hodeidah was attacked by an uncrewed surface vessel that hit its port side, causing some damage and light smoke, the United Kingdom Maritime Trade Operations (UKMTO) said.
The ship and its crew were reported safe and proceeding to next port of call, UKMTO added.
Another merchant vessel, 70 nautical miles southwest of Hodeidah, reported three missiles had exploded nearby, after the ship earlier came under attack by three small craft, UKMTO and security firm Ambrey said separately.
The vessel reported one missile exploding at 0800 GMT, then another two missiles around 45 minutes later, according to UKMTO.
Earlier on Monday, an unmanned small craft collided with the vessel twice and two manned small craft fired at it, UKMTO said.
Both the vessel and crew were also reported as safe and proceeding to the next port of call, Ambrey said.
There was no immediate claim of responsibility for the attack. But since November, Houthi militants in Yemen have launched drone and missile strikes in shipping lanes in the Red Sea and Gulf of Aden. The group says these actions are in solidarity with Palestinians affected by Israel's war in Gaza.
The vessel conducted "self-protection measures," then after 15 minutes the small craft aborted the attack, UKMTO said.
In dozens of attacks since November, the Houthis have sunk two vessels, seized another and killed at least three sailors.
Attacks halt trade
The attacks have upended global trade by forcing ship owners to reroute vessels away from the Suez Canal, and drawn retaliatory U.S. and British strikes since February.
At least 65 countries and major energy and shipping companies have been affected by Houthis attacks, according to a report by the U.S. Defense Intelligence Agency.