A ship was attacked off the coast of Yemen, according to United Kingdom Maritime Trade Operations, which cited reports from vessels in the vicinity
The agency said it was made aware of an attack on a merchant ship on Friday.
The incident came days after an explosion rocked an oil tanker docked at a port in Saudi Arabia.
On Saturday, UKMTO said the crew and vessel in the Yemen incident were safe.
The Gulf of Aden is a crucial route for global trade and was until recently vulnerable to Somali pirate attacks.
The ship went to Yemeni port city of Nishtun after it was attacked.
Ambrey, a British private maritime intelligence firm, identified the vessel as the Sierra Leone flagged MV Hasan, a cargo ship bound for Salalah in Oman.
The Hasan is registered to Oasis Shipping, a Marshall Islands firm with an address linking it to a Beirut address for Barhoum Maritime.
The US Navy's Bahrain-based 5th Fleet, which patrols Middle Eastern waterways, said it was aware of the incident but declined to comment further.
No group claimed responsibility for the attack.
In November, a mine in the Red Sea off Saudi Arabia's coast near Yemen exploded and damaged an oil tanker.
The Greek-operated vessel was docked at Shuqaiq in Saudi Arabia.
Suspicion fell on Yemen's Iranian-backed Houthi rebels, who hold the capital, Sanaa, and have been identified by United Nations analysts as using sea mines in the conflict.