Iran has barred Lebanese planes from repatriating dozens of Lebanese nationals stranded in Iran, escalating tensions after Lebanon had blocked two Iranian civilian flights.

Lebanon halted two Iranian flights to Beirut earlier this week amid suspicions that Tehran might be using civilian aircraft to smuggle funds to Hezbollah. In response, Iran announced it would not allow Lebanese flights to land until its own flights were granted permission to land in Beirut.

Hezbollah supporters staged protests late Thursday and Friday, blocking roads around Beirut’s airport. 

Iranian Foreign Ministry spokesperson Esmaeil Baghaei on Friday accused Israel of threatening a passenger plane carrying Lebanese citizens from Tehran, disrupting normal flight operations to Beirut. He condemned the alleged Israeli threat as a violation of international law.

Israel’s military spokesman Avichay Adraee had claimed that Iran’s Quds Force and Hezbollah had been using civilian flights to smuggle money to Beirut. He reiterated that Israel would "not allow Hezbollah to arm itself and will use all means at its disposal" to enforce a truce requiring Lebanon to halt arms transfers to Hezbollah.

Israeli newspaper Yedioth Ahronoth quoted intelligence sources as saying the Iranian plane barred from landing in Beirut was carrying millions of dollars intended for Hezbollah. The sources claimed that the funds were crucial for the group's operations following heavy losses sustained in recent Israeli attacks.

In a bid to bring the stranded citizens home, Lebanon dispatched two Middle East Airlines planes to Iran on Friday, but Iranian authorities refused to allow them to land. Iran’s ambassador to Beirut, Mojtaba Amani, told state television that Iran would only permit Lebanese flights if Iranian planes were allowed to land in Beirut.

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

Flights from Iran are expected to remain halted until at least Feb. 18, The Wall Street Journal reported, citing sources familiar with the matter.

Lebanese Foreign Minister Joe Rajji told broadcaster Al-Jadeed on Friday that his ministry was working to resolve the issue with its Iranian counterpart. 

Tensions over Iranian flights to Beirut have been simmering for months. In September, Lebanon's transport ministry ordered an Iranian aircraft not to enter its airspace after Israel warned air traffic control it would use "force" if the plane landed.