The United Nations Interim Force in Lebanon on Friday demanded a "full and immediate investigation by Lebanese authorities" Friday after one of its vehicles was torched by Hezbollah supporters on the airport road, wounding its outgoing deputy commander.

"Attacks on peacekeepers are flagrant violations of international law and may amount to war crimes," the UNIFIL peacekeeping force said.

A vehicle emblazoned with the logo of the U.N. peacekeeping force in Lebanon was torched late Friday as supporters of Hezbollah again blocked the road to Beirut airport.

The charred vehicle lay abandoned by the roadside as Lebanese troops deployed in response to the protest and managed to reopen the road and restore order in the area.

Iran accused Israel on Friday of disrupting flights from Tehran to Beirut, after a decision barring two Iranian planes from landing in the Lebanese capital sparked protests.

Israel has repeatedly accused Hezbollah of using Lebanon's only airport to transfer weapons from Iran and struck the area during its war with the Tehran-backed militant group which ended late last year.

The U.S. representative on a committee overseeing the ceasefire agreement that ended the latest Israel-Hezbollah war said Friday that “significant progress” had been made ahead of a looming deadline to implement all the terms of the deal.

However, Maj. Gen. Jasper Jeffers' statement appeared to leave some ambiguity on whether Israel would withdraw its forces from all of southern Lebanon by the ceasefire's Feb. 18 deadline, saying only that he was confident “all population centers in the Southern Litani Area” would be back under Lebanese control by then.

In a speech to a crowd of supporters at his father's tomb on Friday, ex-PM Saad Hariri stopped short of announcing a return to politics, but did say his al-Mustaqbal Movement would "stay with you and be your voice in all national milestones and in all upcoming events."

Thousands of supporters gathered in downtown Beirut Friday to commemorate the 20th anniversary of former Prime Minister Rafik Hariri's assassination, which comes amid seismic regional political shifts.

The ousting of Bashar Assad in December after 54 years of family rule in Syria marked the fall of a government long accused of orchestrating Hariri's assassination and other political killings in Lebanon.

In a desolate area of Syria where Lebanese militant group Hezbollah once held sway, security forces shot open the gates to an abandoned building and found a defunct drug factory.

Syria's new authorities launched a security campaign last week around Qusayr at the porous Lebanese border, cracking down on drug and weapons smugglers.

The Israeli military is prepared to withdraw from Lebanese territory and hand over areas to the Lebanese Army "within the timeline" set by a U.S.-French-mediated ceasefire agreement, a senior Israeli security official said.

Israeli fighter jets overnight hit what the Israeli army said were Hezbollah military sites "containing weapons and launchers, which pose a direct threat to the Israeli home front."

Lebanese media reported that Israeli aircraft had targeted sites near the town of Yater. Warplanes were also seen flying over southern Lebanese villages and towns.

U.N. Secretary-General Antonio Guterres' deputy spokesman Farhan Haq said "we continue to urge Israel and Lebanon to honor their commitments to the cessation of hostilities understanding."

"Continued progress in Lebanese Armed Forces redeployment and Israeli Defense Force withdrawal is crucial," Haq said, adding that "the parties must avoid any action that could raise tensions, endanger civilians and further delay their return to their towns and villages on both sides."