The warning relayed by US diplomatic posts from the FAA underlined the risks the current tensions pose to a region crucial to global air travel. It also came as Lloyd's of London warned of increasing risks to maritime shipping in the region.
US diplomats warned on Saturday that commercial airliners flying over the wider Persian Gulf faced a risk of being "misidentified" amid heightened tensions between the US and Iran.
Meanwhile, oil giant ExxonMobil began evacuating staff from Basra, Iraq, where the US Consulate has been closed for months following a rocket attack America blamed on Shiite militias backed by Iran, local authorities said.
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 nonessential diplomatic staff out of Iraq.
President Donald Trump since has sought to soften his tone. Iranian Foreign Minister Mohammad Javad Zarif also stressed Saturday that Iran is "not seeking war."
But tensions remain. Authorities allege that a sabotage operation targeted four oil tankers off the coast of the United Arab Emirates, and Iran-aligned rebels in Yemen claimed responsibility for a drone attack on a crucial Saudi oil pipeline.
Saudi Arabia directly blamed Iran for the drone assault, and a local newspaper linked to the Al Saud royal family called on Thursday for America to launch "surgical strikes" on Tehran.
This all takes root in Trump's decision last year to withdraw the US from the 2015 nuclear accord between Iran and world powers and impose wide-reaching sanctions.
Iran just announced it would begin backing away from terms of 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.
Tehran long has insisted it does not seek nuclear weapons, though the West fears its program 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 Thursday in the US.
It said that all commercial aircraft flying over the waters of Persian Gulf and the Gulf of Oman needed to be aware of "heightened military activities and increased political tension."
This presents "an increasing inadvertent risk to US civil aviation operations due to the potential for miscalculation or misidentification," the warning said. I
t also said aircraft could experience interference with its 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 United Arab Emirates, home to Emirates, is the world's busiest for international travel, while long-haul carriers Etihad and Qatar Airways also operate in the region.
Emirates, Etihad and Qatar Airways all said they were aware of the notice and their operations were unaffected. Oman Air did not respond to a request for comment Saturday about the warning.
The warning appeared rooted in what happened 30 years ago after Operation Praying Mantis, a daylong naval battle in the Persian Gulf between American forces and Iran during the country's long 1980s war with Iraq.
On July 3, 1988, the USS Vincennes chased Iranian speedboats that allegedly opened fire on a helicopter into Iranian territorial waters, then mistook an Iran Air heading to Dubai for an Iranian F-14. The Vincennes fired two missiles at the airplane, killing all aboard the flight.
Speaking in China, where he finished a tour of Asian nations who rely on Mideast oil, Zarif told the state-run IRNA news agency that war is not what Iran wants.
"In fact, as the supreme leader said, there will be no war since we are not seeking war and nobody in the region is suffering from a hallucination to think that he is able to confront Iran," Zarif said.
Zarif added that while Trump has said that he too is not seeking war, "some that have sat around him" are pushing for such a conflict. That appeared to be a dig at national security adviser John Bolton, who for years has promoted the idea of overthrowing Iran's government.
Meanwhile, Lloyd's Market Association Joint War Committee added the Persian Gulf, the Gulf of Oman and the United Arab Emirates on Friday 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.
Benchmark Brent crude now stands around $72 a barrel.
In Iraq, Exxon Mobil has begun evacuating staff from Basra amid the tensions with Iran, two Iraqi officials told The Associated Press. Exxon Mobil works in Basra at its West Qurna I oil field, which had been shut off for years from Western oil firms over sanctions levied on Iraq during dictator Saddam Hussein's time in power.
The US Consulate in Basra has been closed since September after American officials blamed Iran-aligned Shia militias for a rocket attack on the post, which is inside Basra's airport compound.
Basra as a whole has been shaken by violent protests in recent months over entrenched corruption and poor public services, which earlier saw Iran's Consulate there overrun and set ablaze.
Exxon Mobil, based in Irving, Texas, did not immediately respond to a request for comment.
Iraq is OPEC's second-largest Arab producer, pumping some 4.5 million barrels of crude oil a day.