Israeli air strikes hit a Palestinian group's compound in Lebanon in the early hours of Monday, one day after two drones crashed in the Hezbollah-dominated southern suburbs of Beirut.
The position hit on Monday is reported to belong to the Popular Front for the Liberation of Palestine-General Command and there were no injuries.
An official from the Palestinian position in the Lebanese town of Qusaya said three air strikes hit it, causing only material damage.
On Sunday, two drones crashed in south Beirut. One exploded as it hit a Hezbollah media centre and the other crash-landed but didn't explode.
On Monday, the head of the government's Higher Relief Commission, Maj Gen Mohammad Khair, said the government would support families whose homes were damaged in Sunday's blast after touring the building to speak with residents.
"The Lebanese citizens are always steadfast in the face of this kind of terrorism suffered by the people of Dahiyeh and we are with all the citizens," he said.
Hezbollah Secretary General Hassan Nasrallah decried the incident and warned of repercussions.
The incident came hours after Israel struck targets in Syria, killing two Hezbollah engineers.
Stay here for The National's rolling coverage of the latest developments following the overnight drone attacks, including regional and international reaction.
Lebanon's Aoun says Israeli drone strikes 'declaration of war'
Lebanon's President Michel Aoun said on Monday that two Israeli drone incursions into Lebanese territory were a "declaration of war".
Two drones crashed early on Sunday in southern Beirut in strongholds of the Lebanese Shiite militia Hezbollah.
He said that the country had a right to defend its territory.
"What happened was similar to a declaration of war which allows us to resort to our right to defending our sovereignty," Mr Aoun's office quoted him as saying on Twitter.
The drone incursions prompting the Iran-backed movement Hezbollah to warn Israeli soldiers at the border to await a response.
Who is the PFLP-GC, the Palestinian group targeted by airstikes?
A pro-Syrian militant group, the PFLP-GC was formed in 1968 independently from the Marxist-Leninist PFLP by Ahmad Gibril.
Throughout its fifty-year history, the group has developed a reputation for being a troublemaker in Lebanon and Syria.
"They never had a good reputation," said Mr Mohsen, adding that the group has been involved in a number of conflicts in the region.
The militants entered the 1975 Lebanese civil war which raged for 15 years on the side of the Syrians, gaining notoriety for looting gold from banks in central Beirut.
It also fought against PLO leader Yasser Arafat when he returned to Lebanon in 1983 after being ousted from Beirut the year before. Unlike the PLO, the PFLP-GC does not recognise any peace agreement with Israel.
After the civil war ended in 1990, the PFLP-GC was one of only two Palestinian factions to refuse to disarm, the other being Fatah Al Intifada.
Despite remaining armed, the PFLP-GC’s military power in Lebanon is limited, paling in comparison to ally Hezbollah, which also refused to disarm in the wake of the civil war.
President Aoun met with UN official over "Israeli assault"
Lebanese President Michel Aoun met with the country's United Nations Special Coordinator on Monday to discuss the "Israeli assault on the southern suburbs of Beirut," the presidency said on Twitter.
Lebanon's Iran-backed Hezbollah movement has vowed to respond to what it called an Israeli drone attack in the southern suburbs of Beirut on Sunday.
The Iranian government on Monday condemned recent strikes in Syria, Lebanon and Iraq, which it blamed on Israel.
"Israel has added a new black mark to its record with the recent strikes against Syria, Lebanon and Iraq," Iranian government spokesman Ali Rubaie said.
"Israel must be punished for its recent actions," he said.
The head of the Iranian Quds force, Qassem Suleimani, reacted to Saturday's Israeli air strikes in Syria and the crash of two Israeli drones in a Beirut suburb with a tweet on Sunday, saying that "these were the last struggles" of Israel.
Gen Suleimani posted pictures of himself on Twitter with the caption: "These insane operations are absolutely last struggles of the Zionist Regime" in three languages.
In a tweet, Mr Netanyahu said: "I reiterate: Iran has no immunity anywhere. Our forces operate in every sector against the Iranian aggression. 'If someone rises up to kill you, kill him first.'"
US Secretary of State Mike Pompeo called Mr Netanyahu and reiterated American support for Israel.
"The secretary and the prime minister discussed how Iran is leveraging its foothold in Syria to threaten Israel and its neighbours," the State Department reported.
Prime Minister Saad Hariri said Israeli reconnaissance flights over Beirut are a clear breach of Lebanese sovereignty and the UN resolution that ended the 2006 war.
Mr Aoun said the incident was “further evidence of Israel’s aggressive intentions and its targeting of stability and peace in Lebanon and the region”.
Hezbollah Secretary General Hassan Nasrallah said that Israel cannot intrude on Lebanese airspace without retaliation. For more details on his speech on Sunday, see here.
Lebanese Forces leader Samir Geagea, a staunch critic of Hezbollah, expressed his sympathy to the residents of south Beirut and condemned the Israeli use of drones over Beirut after Sunday's incident.
"I express my deepest sympathy to our people in the southern suburbs and condemned the repeated Israeli breaches of our skies as well as their use of booby-trapped drones against targets in Lebanon," he said.
Numerous ministers and MPs from Lebanese anti-Hezbollah parties called on people to rally around state institutions after Sunday's incident as a means to defend the country against Israeli aggression.
The call to back state institutions is a thinly veiled criticism of Hezbollah, which operates largely outside the official channels.
Amal Movement MP for Beirut's second district, Hani Kobeissy, said that his party — a staunch ally of Nasrallah — did not suggest that Hezbollah was a replacement for the state and while some criticised the group, it was key for national security.
Lebanese MP Ali Osseiran, who represents the Zahrani region in south Lebanon, condemned the overnight strikes in the Bekaa Valley.
"The Lebanese have demonstrated that they will defend their land and the rights of Lebanon," he said. "It is time for the major powers to put an end to the Israeli aggression against Lebanon, especially since the region is already a tinderbox."
Israeli jets over Lebanon
Early Monday morning, the Lebanese military reported heavy surveillance flights over the south and centre of the country throughout the night and early Monday morning.
At around 11.30am Monday morning, the state-run National News Agency reported that an Israeli surveillance drone was seen over the Bekaa Valley town of Baalbeck.
Israeli strikes hit Palestinian group in Lebanon
Around midnight, Israeli air strikes hit a military position belonging to the Popular Front for the Liberation of Palestine-General Command near the Syrian border in east Lebanon, early on Monday.
Pompeo discusses drone incident with Hariri
US Secretary of State Mike Pompeo called Prime Minister Saad Hariri on Sunday evening to discuss the overnight drone crashes in south Beirut.
Mr Hariri's office said that Mr Pompeo "stressed the need to avoid any escalation and to work with all concerned parties to prevent any form of deterioration".
"Hariri expressed Lebanon's commitment to the obligations of international resolutions. ... He stressed the dangers of the continuous Israeli violations of this resolution and of Lebanese sovereignty, and the need to work to stop these violations," the office said.