MOSCOW: Russia said Wednesday there was a "real threat" of violence from Syria spilling over to Lebanon, calling on all parties to avoid fresh unrest at all costs.

"There is a real threat of the conflict spilling over to Lebanon, where, considering history, the ethnic and religious makeup of the population, and the principles on which Lebanon's government is based, everything can have a very bad ending," Foreign Minister Sergei Lavrov told a news conference.

Russia has refused to adopt a tougher position in the UN Security Council against Bashar al-Assad's regime in Syria, drawing criticism from Western leadres who have called on Assad to step down.

Lavrov's statement comes after state media in Syria and Lebanon on Tuesday accused the opposition Free Syrian Army of abducting a group of Shiite Lebanese pilgrims inside Syria. The FSA has denied any involvement.

"It is especially tragic that the conflicts between Shiites and Sunnis begin to be exposed and artificially aggravated," Lavrov added in televised remarks.

"This is a most dangerous development of events which must be avoided at all costs."

Several clashes occurred over the past year in Lebanon's coastal city of Tripoli between Sunni Muslims who back the uprising against Assad's government and the Alawites who support the regime.

Clashes in Beirut left two dead on Monday following the killing of two anti-Assad clerics at an army checkpoint in the north.