Iran's navy seized the oil tanker St. Nikolas on Thursday in the Gulf of Oman, escalating tensions in the Mideast waterways. The vessel was previously known as the Suez Rajan and had been involved in a yearlong dispute that ultimately saw the US Justice Department seize 1 million barrels of Iranian crude oil. The seizure occurred after weeks of attacks by Yemen's Iranian-backed Houthi rebels on shipping in the Red Sea, including their largest barrage ever of drones and missiles on Tuesday. This has raised the risk of possible retaliatory strikes by US-led forces patrolling the vital waterway, especially after a UN Security Council vote condemning the Houthis.

The British military's United Kingdom Maritime Trade Operations received a report from the ship's security manager of armed men boarding the vessel in the waters between Oman and Iran. Satellite-tracking data showed the Marshall Islands-flagged tanker had turned and headed toward the port of Bandar-e Jask in Iran after loading crude oil bound for Turkey. Empire Navigation, the Greek shipping company associated with the Suez Rajan, acknowledged losing contact with the vessel. The company has no knowledge of a court order or the Iranian navy having seized their vessel and has not been contacted by anyone regarding the incident.

The US Navy's 5th Fleet, which patrols the Mideast, did not respond to a request for comment over the incident. Iran has previously seized two tankers near the Strait of Hormuz, including one with cargo for major US oil company Chevron Corp. Since the collapse of Iran's nuclear deal, Iran's ship seizures have intensified, along with assaults targeting shipping in the region. These actions have led to a series of tense encounters in the waterway between Iran and the US. The recent focus has also been on the Houthi attacks in the Red Sea, as well as the departure of an Iranian cargo vessel suspected of being a spying platform.