An Iranian passenger plane flying from Tehran to Beirut on Thursday was “harassed" by fighter jets, Iranian state TV said, saying the plane managed to safely land in the Lebanese capital. A U.S. official later told The Associated Press that an American fighter jet did pass by the Iranian jet, but at a safe distance.

A Lebanese airport official said the flight, Mahan Airline Flight 1152, landed regularly in Beirut on Thursday evening. The official, who spoke on condition of anonymity because he was not authorized to talk to journalists, had no further details.

There were conflicting reports as to what had happened, as Iran initially blamed Israel for the incident. Syrian state media quoted unidentified civil aviation officials in Damascus as saying two jets, suspected of belonging to the U.S-led coalition, “intercepted” an Iranian passenger plane over al-Tanf, in southwestern Syria.

U.S troops fighting Islamic State militants have established a presence in the al-Tanf area since 2016. The U.S. has declared it a so-called de-conflicted zone. Beyond it, Syrian forces and their Iranian allies operate, which makes it a remaining flashpoint in the region.

The reports said the interception forced the pilot to sharply change altitude, flying low and causing slight injuries among some of the passengers.

According to the Iranian TV report, the fighter jets came within a distance of 100 meters (328 feet) of the Iranian Airbus A310. The pilot quickly took the aircraft to a lower altitude to avoid a collision with the jets, the report said.

U.S. Navy Capt. Bill Urban, a Central Command spokesman, later told AP that a U.S. F-15 fighter jet “conducted a standard visual inspection of a Mahan Air passenger airliner at a safe distance of approximately 1,000 meters (3,280 feet) from the airliner this evening.”

“The visual inspection occurred to ensure the safety of coalition personnel at al-Tanf garrison,” Urban said. “Once the F-15 pilot identified the aircraft as a Mahan Air passenger plane, the F-15 safely opened distance from the aircraft.”

Aircraft at that altitude are to maintain a distance of at least 600 meters (2,000 feet) to ensure they don't hit each other, though planes traveling that close together can encounter wake turbulence.

Data from the flight recorded by website FlightRadar24.com showed the airliner climbed from 34,000 feet to 34,600 feet in under two minutes around the time of the incident, then dropped back down to 34,000 feet within a minute after.

The aircraft landed soon after this but three passengers sustained injuries and were taken to hospital, the TV report said, citing what it described as informed but unnamed sources at the Beirut airport. The report also said some of the cabin crew were injured but did not elaborate.

Iranian state TV quoted the pilot of the Iranian plane as saying the fighter jets' pilots had identified themselves as American over radio communication.

Iran’s Foreign Ministry said that following the incident, a protest note was sent to the Swiss Embassy, which represents America’s interests in Iran, warning that if any accident happens on the plane's return flight to Tehran, it will be the responsibility of the United States.

The ministry's spokesman, Abbas Mousavi, said Iran is investigating the incident. The same note was also delivered to the U.N. Secretary-General António Guterres by Iran’s ambassador to the United Nations, Majid Takht-e Ravanchi.

All this comes amid heightened tensions between Iran and the U.S. after President Donald Trump unilaterally withdrew from Tehran's nuclear deal with world powers over two years ago.

In the time since, a series of escalating incidents have occurred across the Mideast between the two countries, including the U.S. killed an Iranian general in a drone strike and Tehran launching ballistic missiles targeting American forces in Iraq.