Iran steps up claim to control Strait of Hormuz

Iran has said it is significantly expanding the area around the Strait of Hormuz over which it claims military control in an effort to assert its sovereignty of the key trade route.

A map published by Iran's newly-created "Persian Gulf Strait Authority" claims "Iranian armed forces oversight" across more than 22,000 sq km (8,800 sq miles).

It extends into the territorial waters of Oman and the UAE. The UAE described Iran's claims of control as "nothing but fragments of dreams".

Iran's new authority added that all transit through the strait "requires coordination with and authorization from the Persian Gulf Strait Authority".

The US and Gulf allies have repeatedly rejected Iranian attempts to assert control over the strait. The US has told ships not to comply with Iran's rules.

The diplomatic adviser to the UAE president, Anwar Gargash, said Iran is "trying to consecrate a new reality born from a clear military defeat, but attempts to control the Strait of Hormuz or encroach on the UAE's maritime sovereignty are nothing but fragments of dreams".

Under the United Nations Convention on the Law of the Sea ships are guaranteed safe passage through another country's waters - but Iran has not ratified this convention.

Media linked to Iran's Islamic Revolutionary Guard Corps (IRGC) this week published footage showing what it claimed was a "punishment" strike on a tanker in the strait.

BBC Verify analysis shows key characteristics of the vessel in the footage match with Barakah, a Liberian-flagged tanker which reported being struck by unknown projectiles in early May, according to the ship's operators.

Iran's push for greater control over the area around the Strait of Hormuz comes as US forces boarded an Iran-bound oil ‌tanker on Wednesday. The US military's Central Command (Centcom) said it was ⁠suspected of violating the American blockade of Iranian ports.

Footage published by Centcom shows US marines rappelling from a helicopter on to the deck of a ship, said to be the oil tanker Celestial Sea, in the Gulf of Oman.

In a post on social media Centcom said the ship was "suspected of attempting to violate the US blockade by transiting toward an Iranian port".

"US forces subsequently released the vessel after conducting a search and directing the crew to alter course," according to maritime risk management company Vanguard.

Celestial Sea has previously been sanctioned under a previous name by the US for its links with Iran.

Tracking data from MarineTraffic shows the ship is now reporting its destination as the port of Duqm in Oman.

Centcom said it has redirected 91 commercial ships since the US blockade of Iranian ports came into effect on 13 April.

Donald Trump said on Monday he was holding off a military attack on Iran planned for the following day at the request of Gulf states because "serious negotiations are now taking place".