London: Armed men boarded a ship off the Iranian coast on Tuesday before letting it continue its course, a UK-based maritime organisation said on Tuesday.
UK Maritime Trade Operations sounded the alarm after the boat was boarded while anchored off Iran's southeast coast in the Strait of Hormuz.
The vessel was later released under the control of the ship's captain and vessel and crew were safe, the UKMTO reported online, adding: "All vessels in the vicinity are to stay vigilant."
Maritime security analysts Dryad Global reported the same incident, saying there were 22 crew aboard who were understood to be Chinese nationals.
Tensions remain high in the region after Iran was accused by the US in June last year of attacking oil tankers in the Gulf of Oman, a claim denied by Tehran.
Those claims came during a time of increased diplomatic tensions between the US and Iran.