Syria's main opposition group called Sunday on Hizbullah fighters to defect, as members of Lebanon's party led an assault on al-Qusayr in central Syria and a day after its leader vowed victory.

Hizbullah, a key ally of Syrian President Bashar Assad's regime, "repeats Assad's grievous mistake of forcing his people to kill innocent Syrians, which will undoubtedly lead the honorable members of Hizbullah to defect and stand by the truth," said a statement from the Syrian National Coalition.

"The Syrian Coalition hopes for peace for the people of Lebanon and rejects Hizbullah's call to turn the Syrian revolution into a regional conflict," the opposition group added.

On Saturday, Hizbullah leader Sayyed Hassan Nasrallah vowed "victory" in the battles raging in neighboring Syria in a speech to mark the 13th anniversary of the Israeli withdrawal from southern Lebanon.

"I say to all the honorable people, to the mujahedeen, to the heroes: I have always promised you a victory and now I pledge to you a new one" in Syria, he said.

"Syria is the rear guard of the resistance (Hizbullah's fight with Israel), its backbone, and the resistance cannot stay with its arms folded when its rear guard is exposed."

The Syrian opposition said Nasrallah "has used ideological, extremist, and fringe rhetoric in order to push followers of Hizbullah into a war based on deception, false legacies and lies, driving the group to death and destruction."

Hizbullah has joined a Syrian army and paramilitary assault on rebel bastion al-Qusayr, which is strategic because of its proximity to the Lebanese border and because it lies near the route linking Damascus to the coast.

The group has reportedly sent 1,700 men to fight in Syria, sparking outrage among Western states.

Syria's conflict has spilled over into Lebanon, which was dominated by Damascus for 30 years until 2005. Through his allies, Assad continues to exert significant influence over the small Mediterranean country.

Thirty people have died in six days of battles in the northern Lebanese port city of Tripoli, pitting Sunnis who back the Syrian rebellion against Alawites who back Assad, a Lebanese security source said Saturday.

Four people were wounded in Lebanon Sunday when two rockets exploded in the Shiite-majority Hizbullah heartland of south Beirut, a second security source said.

"This incident is probably related to the conflict in Syria," the source added.