Former premier Saad Hariri said Saturday Lebanon's Sunni Muslims refuse to be a part of any conflict between Al-Qaeda and Shiite movement Hezbollah, denouncing sectarian attacks on civilians anywhere in the country.
The war in neighbouring Syria has inflamed sectarian tensions in Lebanon, with Hezbollah backing President Bashar al-Assad and many Sunnis supporting the rebellion against him.
Hariri's statement came a day after a jihadist group warned that all areas where Hezbollah operates are "legitimate targets", telling Sunnis to avoid them.
It also came as new shelling from across the border hit the Hermel and Masharia al-Qaa areas of Lebanon's Bekaa Valley, causing no casualties.
Al-Nusra Front in Lebanon and another jihadist group claimed responsibility for the shelling.
"The Lebanese, and the Sunnis among them, refuse to be part of any war in Lebanon or the region between Hezbollah and Al-Qaeda," said Hariri, who heads the anti-Syrian Future bloc.
"They also refuse that the civilians in any region of Lebanon become the targets," he added.
On Friday, Al-Nusra Front in Lebanon, a group suspected of links to Al-Qaeda, described Hezbollah's "bases and bastions" as "legitimate targets".
It claimed a car bomb attack in Beirut's southern suburbs on Tuesday that killed four people.
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It was the sixth in a string of attacks targeting areas dominated by Hezbollah since the group acknowledged sending fighters into Syria to support Assad's forces.
Al-Nusra Front in Lebanon -- believed to be the local franchise of Syria's Al-Nusra Front, a jihadist rebel movement -- had previously claimed responsibility for a car bombing in Hermel in eastern Lebanon, which killed three people.
While Hezbollah is said to be the target of such attacks, they have regularly killed civilians.
Hariri on Saturday reiterated his opposition to Hezbollah's support for Assad, whom he has accused of ordering the assassination of his father, former premier Rafiq Hariri.
"Every sane and patriotic Lebanese, of any sect, will refuse to be dragged behind these (jihadist) calls, (just) as he refuses Hezbollah's war in Syria," Hariri said.
Also on Saturday, another salvo of shells hit the Bekaa Valley, which has suffered frequent cross-border assaults.
"Eight shells hit the outskirts of Hermel, while one landed inside the town, causing material damage to vehicles and houses," a security source said.
"Three mortar rounds also struck the outskirts of Masharia al-Qaa" east of Hermel, the source added.
Al-Nusra Front in Lebanon and the Marwan Hadid brigades, another jihadist group, claimed the latest attacks.
"Al-Nusra Front in Lebanon and the Marwan Hadid brigades... announce that the Grad missile attack... on Hermel has achieved its goal," the groups said on Twitter.
They warned that attacks on Hezbollah-controlled areas will continue until Lebanon releases Sunni Islamist prisoners and Hezbollah withdraws from Syria.