Live updates: Follow the latest on Israel-Gaza
At least two people, including a commander in the Fajr Forces, the military wing of the Islamic Group in Lebanon, were killed in Israeli strikes on Lebanon on Thursday morning.
Muhammad Hamid Jabara, from Qaraoun, was killed in the strike on his pick-up truck as he drove through the town of Ghazzeh, in the western Bekaa region, the group said.
The Islamic Group said in a statement that Mr Jabara was killed “in a treacherous Zionist raid”.
“We, in the Islamic Group, as we mourn for our nation and our people our martyred mujahid Muhammad Hamid Jabara [Abu Mahmoud], hold the Zionist enemy responsible for this cowardly crime,” the group said.
“We affirm that it will not deter us from carrying out our role and duty in defending our land and our people in the south, nor from supporting our people in Palestine.”
The Israeli army said its strike killed a Hamas operative "responsible for carrying out terror attacks and missile launches" against Israel. Those included attacks co-ordinated with the Islamic Group, the army said.
But a representative of the Fajr Forces told The National that Mr Jabara was a member of the Islamic Group. A member of Hamas said the commander "worked with us as well".
Hamas and the Islamic Group, both offshoots of the Muslim Brotherhood, have co-ordinated closely in Lebanon since last October, when Hezbollah and its allies began exchanging cross-border fire with Israel.
The Islamic Group was formed in the 1960s, while its armed wing was established in 1982 to fight against Israel's invasion of Lebanon.
The group had a resurgence in October, entering into a strategic alliance with Hezbollah. The Fajr Forces have since been responsible for several attacks against Israel.
Israel launched drone attacks on two additional sites on Thursday morning, Lebanon's National News Agency reported.
An Israeli drone strike killed one person in a car in Jbal Al Botm, in the Tyre district. Images circulated online showed a white vehicle on fire as ambulances and rescue workers surrounded it.
Rescue workers said the man in the car was taken to a nearby hospital after the attack. His identity is not yet known.
In the second incident, an Israeli raid on Wadi Al Azziyeh, on the outskirts of the southern Lebanese village of Zebqine, hit a reportedly uninhabited building, starting a fire, the state news agency reported. Firefighting teams were dispatched to the site.
Tension across the Lebanon-Israel border has intensified after a brief lull. The conflict escalated this week after the death of seven civilians in Lebanon over two days, with Hezbollah responding with dozens of rocket strikes on northern Israel.
Since October, the conflict on the Lebanon-Israel border has killed 512 people in Lebanon, mostly fighters, including nine from the Fajr Forces, an AFP tally shows. At least 104 civilians have been killed by Israeli strikes on Lebanon.
In Israel, authorities say at least 17 soldiers and 13 civilians have been killed in the violence.