Britain was weighing its next moves in the Gulf tanker crisis on Sunday, with few good options apparent as a recording emerged showing that the Iranian military defied a British warship when it boarded and seized a ship three days ago.
A British warship radioed an Iranian patrol boat to warn against interfering with the Stena Impero as the oil tanker passed through the Strait of Hormuz, according to a recording obtained by Reuters.
Tensions between Iran and the West have escalated since U.S. sanctions on Iranian oil exports took full effect in May and British naval forces seized an Iranian supertanker.
Britain on Saturday denounced Iran's seizure of a British-flagged oil tanker in the Gulf as a "hostile act" and rejected Tehran's explanation that it seized the vessel because it had been involved in an accident.
Panama's maritime authority said on Saturday it had begun the process of withdrawing the registration of an oil tanker called MT Riah, which was towed to Iran after it disappeared from ship tracking maps in the Strait of Hormuz on July 14.
Britain told the United Nations Security Council on Saturday that a British-flagged tanker seized by Iran was approached by Iranian forces when it was in Omani territorial waters and the action "constitutes illegal interference."
Saudi Arabia said on Saturday it had sent a crew member of an Iranian ship who was previously evacuated for medical reasons from a vessel off the Yemeni port of Hodeidah, to Oman.
Britain said Iran seized two oil tankers in the Gulf on Friday and told Tehran to return the vessels or face consequences in the latest confrontation to ratchet up tension along a vital international oil shipping route.
British foreign minister Jeremy Hunt said on Saturday that he was worried that Iran had taken a "dangerous path" after it seized a British-flagged tanker on Friday in the Strait of Hormuz.
Iran said it had seized a British oil tanker in the Strait of Hormuz on Friday but denied Washington's assertion that the U.S. Navy had downed an Iranian drone nearby this week, as tensions in the Gulf region rose again.