US diplomats have warned commercial flights over the Persian Gulf face a risk of being "misidentified" amid simmering tensions between Washington and Iran.
An advisory, issued by the Federal Aviation Administration (FAA) and relayed by US diplomatic posts, said the warning came amid "heightened military activities and increased political tensions in the region".
Those tensions "present an increasing inadvertent risk to US civil aviation operations due to the potential for miscalculation or misidentification”, the advisory added.
It came as Lloyd's of London, a world-leading insurance market, warned of increased risks to shipping in the region.
Concerns about a possible conflict have flared since the White House ordered warships and bombers to the region to counter an alleged, unexplained threat from Iran that has seen America order non-essential diplomatic staff out of Iraq.
Donald Trump has since sought to soften his tone. On Friday afternoon he accused mainstream media of publishing "made up news" and of leaving Iran with "no idea what is actually going on". He provided no evidence to back up his claim.
"The Fake News Media is hurting our Country with its fraudulent and highly inaccurate coverage of Iran," he tweeted. "It is scattershot, poorly sourced (made up), and DANGEROUS. At least Iran doesn’t know what to think, which at this point may very well be a good thing!"
The Fake News Media is hurting our Country with its fraudulent and highly inaccurate coverage of Iran. It is scattershot, poorly sourced (made up), and DANGEROUS. At least Iran doesn’t know what to think, which at this point may very well be a good thing!— Donald J. Trump (@realDonaldTrump)May 17, 2019
Iranian foreign minister Mohammad Javad Zarif said on Saturday he did not believe a war would break out in the region as Tehran did not want a conflict and no country had the "illusion it could confront Iran", the state news agency IRNA reported.
"There will be no war because neither we want a war, nor has anyone the idea or illusion that it can confront Iran in the region," Mr Zarif told IRNA before ending a visit to Beijing.
Meanwhile, Saudi authorities allege a sabotage operation targeted four oil tankers off the coast of the United Arab Emirates (UAE), and Iran-aligned rebels in Yemen claimed responsibility for a drone attack on a crucial Saudi oil pipeline.
Saudi Arabia blamed Iran for the drone assault, and a local newspaper linked to the Al Saud royal family called for America to launch "surgical strikes" on Tehran.
Much of the current tension stems from Mr Trump's decision last year to withdraw the US from the 2015 nuclear accord between Iran and world powers and impose wide-reaching sanctions.
Tehran has since announced it will begin withdrawing from the deal, setting a 60-day deadline for Europe to come up with new terms or it would begin enriching uranium closer to weapons-grade levels.
The Islamic Republic has long insisted it does not seek nuclear weapons, but the West fears its programme could allow it to build atomic bombs.
The order relayed on Saturday by US diplomats in Kuwait and the UAE came from an FAA Notice to airmen published late on Thursday in the US. It said that all commercial aircraft flying over the waters of the Persian Gulf and the Gulf of Oman needed to be aware of the increased risks.
It said aircraft could experience interference with navigation instruments and communications jamming "with little to no warning".
The Persian Gulf has become a major gateway for East-West travel in the aviation industry. Dubai International Airport in the UAE, home to Emirates, is the world's busiest for international travel, while long-haul carriers Etihad and Qatar Airways also operate there.
In a statement, Emirates said it was aware of the notice and in touch with authorities worldwide, but "at this time there are no changes to our flight operations".
Meanwhile, Lloyd's Market Association Joint War Committee added the Persian Gulf, the Gulf of Oman and the United Arab Emirates to its list of areas posing higher risk to insurers. It also expanded its list to include the Saudi coast as a risk area.
The USS Abraham Lincoln and its carrier strike group have yet to reach the Strait of Hormuz, the narrow mouth of the Persian Gulf through which a third of all oil traded at sea passes.
A Revolutionary Guard deputy has warned that any armed conflict would affect the global energy market. Iran long has threatened to be able to shut off the strait.
Additional reporting by agencies