As a result, the UK has raised the threat level for British ships in the Gulf to its highest level of “critical”.
US officials believe the boats which approached the tanker as it moved out of the Gulf into the Straits of Hormuz belong to the Iranian Revolutionary Guard Corps (IRGC). The Strait of Hormuz is the narrow route in which a fifth of the world’s oil supply is transported.
The incident comes after Royal Marines seized an Iranian oil tanker off the Straits of Gibraltar on 4th July. The Grace-1 super-tanker was believed to be heading toward Syria to deliver oil in defiance of EU sanctions.
An MOD spokesperson said: “Contrary to international law, three Iranian vessels attempted to impede the passage of a commercial vessel, British Heritage, through the Strait of Hormuz”. The type 23 British frigate, HMS Montrose, was “forced to position herself between the Iranian vessels and British Heritage and issue verbal warnings to the Iranian vessels, which then turned away”. The statement added: “We are concerned by this action and continue to urge the Iranian authorities to de-escalate the situation in the region”.
Prime Minister Theresa May’s official spokesman said the government was “committed to maintaining freedom of navigation in accordance with international law”. Foreign Secretary Jeremy Hunt called the Iranian move a “very concerning development” and said the British Government is “continuing to monitor the situation very, very carefully”.
The Iranian foreign Minister, Mohammad Javad Zarif, dismissed the claims as “worthless,” and accused the UK of “creating tension”. Iranian sources had last week called the capture of their tanker “unnecessary and non-constructive escalation by the UK”. President Hassan Rouhani called Britain “an initiator of insecurity and you will understand its repercussions”.
This situation comes amid a difficult situation globally relating to Iran. Over the past year, the US and Iran have been locked in dispute over sanctions and there have been several tense escalations, including an attack on a US tanker in the Gulf of Oman in June. Iran has recently breached the Nuclear Accords in an attempt to scare other countries into relaxing sanctions.