A group of armed men in "military-style" uniforms reportedly boarded an oil tanker off the Gulf of Oman on Thursday, a U.K.-based maritime risk management company said.
In the latest spate of shipping incidents in the region, the Marshall Islands-flagged St. Nikolas was boarded at about 7:30 a.m. (3.30 a.m. GMT) 50 nautical miles east of Sohar in Oman and then headed toward Bandar-e-Jask in Iran, according to British firm Ambrey.
"The individuals covered the vessel's cameras," Ambrey reported, adding that a security officer "reported hearing unknown voices over the phone along with the master's voice."
"The armed suspects are reportedly wearing 'military-style black uniforms with black masks,'" it added.
The incident was also reported by United Kingdom Maritime Trade Operations, a British maritime security agency.
The St. Nikolas was sailing from the Iraqi port of Basra to Türkiye, according to Marine Traffic, a tracking website.
Ambrey said the recently renamed tanker was previously prosecuted and fined for carrying sanctioned Iranian oil, which was confiscated by U.S. authorities.
"Iran has previously taken action against those it has accused of cooperating with the U.S.," it added.
The Gulf of Oman, a key route for the oil industry that separates Oman and Iran, has witnessed a series of hijackings and attacks over the years, often involving Iran.
Shipping in the resource-rich region is also on heightened alert following weeks of drone and missile attacks by Yemen's Houthi rebels in the Red Sea.
Earlier Wednesday, The United Nations Security Council demanded an immediate end to the Houthi attacks on shipping.
The resolution passed "demands that the Huthis immediately cease all such attacks, which impede global commerce and undermine navigational rights and freedoms as well as regional peace and security."
It passed after Russia, as well as China, Mozambique and Algeria abstained.