Lebanese authorities said Saturday that more than 25 people had been arrested following an attack on a United Nations convoy the day before that wounded two peacekeepers, including the force's outgoing deputy commander.
UN and Lebanese officials have condemned Friday's attack, which came as Hezbollah supporters for a second night blocked the road to the country's only international airport over a decision barring two Iranian planes from landing there.
"More than 25 people have been arrested by Lebanese army intelligence", with another person detained by the security services, Interior Minister Ahmad al-Hajjar told reporters after an emergency security meeting Saturday, AFP reported.
"This does not mean these detainees carried out the attack... but the investigations will show who is responsible," he said.
The army and security agencies would bolster measures to "maintain security and stability", Hajjar added, and violations would be treated "with all seriousness".
The UN Interim Force in Lebanon (UNIFIL) has demanded an investigation after one of its vehicles was set on fire during the incident, which wounded outgoing deputy force commander Chok Bahadur Dhakal, a Nepalese national who was heading home after ending his mission.
UNIFIL deputy spokesperson Kandice Ardiel told AFP a second Nepalese peacekeeper was also wounded and hospitalized.
In a meeting with Hajjar on Saturday, Prime Minister Nawaf Salam emphasized the importance of maintaining security across the country, a statement from his office said. The premier was set to meet other "relevant ministers" later in the day.
The presidency's statement said the Lebanese president had stressed that the incident "cannot be allowed to be repeated", adding that the judiciary "has begun investigations on the ground".
The army said Friday that several areas around the airport had seen "demonstrations marked by acts of vandalism and clashes, including assaults on members of the armed forces and attacks against vehicles".
Videos circulating on social media showed demonstrators, some hooded and carrying Hezbollah flags, attacking a man in military garb and another in civilian clothes near the torched UNIFIL vehicle.
It remains unclear who was responsible for the attack.
There was no immediate official comment from Hezbollah, but its television channel Al-Manar late Friday blamed unidentified "masked men".
It said the protesters expressed "their rejection of the attack on the UNIFIL convoy", adding their goal was "to secure the return of citizens stuck in Iran".
The group's ally the Amal movement, led by powerful parliament speaker Nabih Berri, said "the attack on UNIFIL is an attack on south Lebanon" and that "blocking roads anywhere is an assault on civil peace".
Several countries have condemned the incident, as did UN chief Antonio Guterres.
"Such attacks are absolutely unacceptable... The safety and security of UN personnel and property must be respected at all times," his spokesman, Stephane Dujarric, said in a statement.
"Attacks against peacekeepers are in breach of international law... and may constitute war crimes," the statement said, adding that "UNIFIL must be allowed unrestricted freedom of movement throughout Lebanon".