(Adds UK investigating incident, remarks by Saudi minister)
By Lisa Barrington and Jonathan Saul
DUBAI/LONDON, Aug 3 (Reuters) - Iranian-backed forces are believed to have seized an oil tanker in the Gulf off the coast of the United Arab Emirates, three maritime security sources said, after Britain's maritime trade agency reported a "potential hijack" in the area on Tuesday.
Two of the sources identified the vessel as the Panama-flagged asphalt/bitumen tanker Asphalt Princess in an area in the Arabian Sea leading to the Strait of Hormuz, the conduit for about a fifth of the world's seaborne oil exports.
Iran's Foreign Ministry had earlier said reports of security incidents involving several ships near the UAE coast on Tuesday were "suspicious", and it warned of any effort to create a "false atmosphere" against the Islamic Republic.
Tensions have simmered in the region after an attack last week on an Israeli-managed tanker off the Omani coast killed two crew members and was blamed on Iran by the United States, Israel and Britain. Iran denied responsibility.
The Bahrain-based U.S. Navy's Fifth Fleet and UAE authorities did not immediately reply to a Reuters request for comment about Tuesday's incident.
The United Kingdom Maritime Trade Operations (UKMTO), in a warning notice based on a third party source, had earlier reported a "potential hijack" and advised ships to exercise extreme caution due to the incident around 60 nautical miles east of the UAE's Fujairah emirate.
Britain's foreign ministry is "urgently investigating" an incident on a vessel off the UAE coast, a spokesperson said.
The Times of London newspaper also reported that the Asphalt Princess had been hijacked, citing British sources as saying they were "working on the assumption Iranian military or proxies boarded the vessel".
Alluding to the reports, Saudi Arabia's foreign minister told a U.S. think tank in an online appearance that he sees an emboldened Iran acting in a negative manner in the region, including endangering shipping.
On Tuesday at least five ships in the sea between the UAE and Iran updated their AIS tracking status to "Not Under Command", according to Refinitiv ship tracking data. Such a status generally indicates a ship is unable to manoeuvre due to exceptional circumstances.
Reuters could not confirm this Refinitiv data had any connection to the reported incident.
The United States and Britain said on Sunday they would work with their allies to respond to last week's attack on the Mercer Street, a Liberian-flagged, Japanese-owned petroleum product tanker managed by Israeli-owned Zodiac Maritime.
Iran denied involvement in that suspected drone strike and said it would respond to any threat against its security.
Tensions have risen in Gulf waters and between Iran and Israel since 2018, when then-President Donald Trump withdrew the United States from Tehran's 2015 nuclear deal with six world powers and reimposed sanctions that have crippled its economy.
Iran and Israel, longtime adversaries, have exchanged accusations of carrying out attacks on each other's vessels in recent months. (Additional reporting by Dubai newsroom, Elizabeth Piper in London and Arshad Mohammed and Daphne Psaledakis in Washington; Editing by Ghaida Ghantous and Mark Heinrich)
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