The United Kingdom Maritime Trade Operations (UKMTO) organization said it received a report on Sunday of an approach involving two small crafts 23 nautical miles (43 kilometers) northwest of the Red Sea Eritrean port city of Assab.
"The two small boats approached and hailed a merchant vessel, attempting to get them to change course," UKMTO said in an advisory.
"The merchant vessel maintained course, post reassurance from authorities. The two small boats have now left vicinity. Vessel and crew are safe," it added.