A roadside bomb targeted on Monday a Hizbullah passenger van from Lebanon to Syria, reported LBCI television.

It said that the explosive was placed in an alley behind the Customs building in the Bekaa town of Chtaura.

Turkey warned Russia on Monday against violations of its airspace by warplanes straying over the border from Syria, as NATO called an emergency meeting over the "unacceptable" intrusion.

Ankara, a NATO member, protested to Moscow after its F-16 jets intercepted a Russian fighter plane that violated its air space near the Syrian border over the weekend, forcing it to turn back.

Syrian President Bashar Assad said in comments broadcast on Sunday that the success of Russia's military intervention in his country's civil war was vital for the whole Middle East.

"The alliance between Russia, Syria, Iraq and Iran must succeed or else the whole region will be destroyed," he said in an interview broadcast by Iranian state television.

French Prime Minister Manuel Valls urged Russia on Sunday to direct air strikes at Islamic State jihadists alone in Syria, as the West raises concerns Moscow will target moderate rebel groups opposed to Syria's president.

Speaking to journalists on a visit to Japan, Valls said Russia should not "get the wrong targets", echoing the words of French President Francois Hollande to Russian President Vladimir Putin at a Paris summit on Friday.

Russia is backing "butcher" President Bashar al-Assad with airstrikes that are often not aimed at Islamic State (IS) fighters in Syria, Britain's Prime Minister David Cameron said Saturday.

Cameron said Russian forces were "making the situation worse" as they pressed a bombing campaign in the IS stronghold for a fourth day. 

Turkish President Recep Tayyip Erdogan on Saturday urged Russian counterpart Vladimir Putin to reconsider Moscow's bombing campaign in Syria, accusing the Russian military of turning a blind eye to the killing of dozens of civilians.

Speaking in an interview with Al-Jazeera Arabic, Erdogan expressed anger that whereas Moscow had informed Ankara it would be attacking Islamic State (IS) jihadists in Syria, it had in fact targeted moderate Syrian rebels.

Russia bombed the Islamic State group's Syrian stronghold Saturday and vowed to press its aerial campaign despite criticism from Washington and its allies that its military action was strengthening the jihadists.

A long-time staunch backer of Syrian President Bashar Assad, Russia began sorties over its ally on Wednesday in what it said would be a prolonged bombing campaign against IS and other extremist groups.

Only one in 20 Russian air strikes in Syria have targeted Islamic State (IS) fighters, Britain's Defense Secretary Michael Fallon said Saturday.

British intelligence services observed that five percent of the strikes had attacked the militant jihadist group, with most "killing civilians" and Free Syrian forces fighting against the regime of president Bashar Assad, Fallon told the Sun newspaper.

The escalation in the conflict in Syria with Russia launching air strikes in the country has raised tensions in the region and concerns that Lebanon may be affected by them, reported al-Joumhouria newspaper on Saturday.

A prominent leader working on a government settlement told the daily: “The negative aspect of the tensions in Lebanon is that they coincide with great foreign escalation.”

Russia carried out a third day of air strikes in Syria on Friday and said it had hit Islamic State's 'capital' as President Vladimir Putin faced mounting international criticism over his military campaign.

Moscow said it had bombed "an IS training camp" and a command post in the IS bastion f Raqa on Thursday, but on Friday it targeted rebel groups opposed to Syrian President Bashar Assad.