After the Israeli military accused Tehran of using civilian aircraft to smuggle cash to Beirut to arm Hezbollah, the latest development to a days-long standoff between Iran and Lebanon that sees both countries blocking flights from landing in their capitals.

Iran barred Lebanese planes from repatriating dozens of Lebanese nationals stranded in Iran on Friday, in the latest development in an ongoing standoff that includes Lebanon and Israel. The move comes after Lebanon blocked an Iranian civilian flight, following what Tehran described as an Israeli threat to attack it.

Lebanon halted an Iranian flight to Beirut this week after the Israeli military accused Tehran of using civilian aircraft to smuggle cash to Beirut to arm Hezbollah. Naim Qassem, Hezbollah's leader, said on Sunday that Israel sent a message to the Lebanese government, saying it would attack the Beirut airport if the Iranian plane lands there.

Iran said it would not allow Lebanese flights to land until its own flights were cleared to land in Beirut.

The standoff has left dozens of Lebanese citizens stranded in Iran for three days after attending a religious pilgrimage. They had been due to return to Beirut on Iran's Mahan Air, before Lebanon barred the plane from landing.

Dozens of Hezbollah supporters cut off roads around Beirut's airport late on Thursday and Friday in protest.

The outgoing deputy force commander of the United Nations Interim Force in Lebanon was injured on Friday after a convoy taking peacekeepers to the airport was "violently attacked," the mission said.

UNIFIL demanded a full and immediate investigation by Lebanese authorities and for all perpetrators to be brought to justice, it said in a statement. Lebanon's Prime Minister Nawaf Salam and the country's army both condemned the attack in separate statements and said urgent measures would be taken to identify and arrest the attackers and prevent any violation of civil peace.

Iranian Foreign Ministry spokesperson Esmaeil Baghaei said on Friday that Israel had threatened a passenger plane carrying Lebanese citizens from Tehran, "which caused a disruption in the country's normal flights to Beirut airport". He condemned the alleged Israeli threat as a violation of international law.

In a post on X, Israel's military spokesman Avichay Adraee said Iran's elite Quds Force and Hezbollah had used civilian flights to smuggle funds to Beirut.

Israel's military would "not allow Hezbollah to arm itself and will use all means at its disposal" to enforce a truce that requires Lebanon to halt arms transfers to Hezbollah, Adraee said.

After blocking the Iranian flight, Lebanon dispatched two planes on Friday from its own national airliner, Middle East Airlines, to bring the stranded Lebanese home from Iran, but Iran refused to allow the Lebanese aircraft to land on its territory.

Iran's ambassador to Beirut, Mojtaba Amani, told Iran's state television on Friday that Iran would allow the planes to land only if Iranian flights were allowed to travel to Beirut.

"For sure the Lebanese government's request will be accepted, but on condition that they do not impede Iranian flights," he said.