Tensions have escalated in Beirut after demonstrators carrying Hezbollah flags blocked the main route to Rafik Hariri International Airport on Thursday evening, February 13, protesting against Lebanon's decision to prevent an Iranian aircraft from landing in the country, according to the state-run news agency.

Local media reported that Iran's Mahan Air was informed that a scheduled flight from Tehran to Beirut would not receive the necessary permission to land, resulting in the journey's cancellation.

In a significant development, large reinforcements from the Lebanese Army's Commando Regiment and the Information Branch's strike force were deployed near the airport with strict instructions from the highest levels, namely that closing Beirut Airport is considered a "red line."

A Hermes 900 reconnaissance aircraft was spotted flying silently over the capital Beirut, whilst the Lebanese Army took measures to reopen the airport road and restore normal traffic flow after protesters had blocked it with burning tyres. Clashes erupted between the army and some protesters on the road.

These incidents coincided with two Israeli raids in the vicinity of the Yahmour River, and a violent strike along the Litani River between East Suter and Deir Syrian, according to preliminary information. There have also been recent reports of preparations to close the Choueifat (Beirut) road.

The escalation follows extensive security checks on planes and passengers arriving in Lebanon from Iran and Iraq, and comes ahead of the funeral of late Hezbollah leader Hassan Nasrallah and his successor Hashem Safieddine, which is expected to draw thousands from Baghdad and Tehran on February 23.

An official at Beirut Airport confirmed to AFP that the Ministry of Public Works and Transport had asked the facility to inform Mahan Air that Lebanon could not accommodate two flights to Beirut. "One flight was scheduled to take off on Thursday and another on Friday," said the official, who asked not to be identified to discuss sensitive matters, adding that "both flights have been rescheduled to next week," without specifying why.

Earlier in the day, video footage circulated online showing a Lebanese man stranded at Tehran Airport urging his citizens to block the Beirut airport road. "We've been waiting here since this morning. We are Lebanese... No one can control us," he said, and also demanded that Hezbollah-allied Parliament Speaker Nabih Berri secure the safe return of Lebanese travellers.

The November 27 ceasefire ended more than a year of hostilities between Israel and Hezbollah, including about two months of all-out war, but both sides regularly accuse each other of violations.

Saeed Shalandari, chief executive of Tehran's Imam Khomeini Airport, told Mehr News Agency in an interview: "Today's flight to Beirut was scheduled to depart... But the destination did not issue the necessary permission."

The day before, IDF spokesman Avichai Adraei claimed that Iran's Quds Force and Hezbollah had been "exploiting ... over the past few weeks, Beirut International Airport has been flying through civilian flights, smuggling money intended to arm" the group.

He added that the IDF was sending information to the committee tasked with ensuring that ceasefire violations were identified and addressed in order to "thwart" such attempts, although some had succeeded.

Israel has repeatedly accused Hezbollah of using Lebanon's only airport to transport weapons from Iran, allegations denied by Hezbollah and Lebanese officials, while authorities have stepped up surveillance and inspection of the facility.

In January, an Iranian plane carrying a diplomatic delegation was searched, angering Hezbollah and its supporters and praising its critics.