Peace envoy Lakhdar Brahimi on Saturday pressed Damascus for a truce to break the cycle of bloodshed, as Lebanon's opposition blamed President Bashar Assad for a deadly Beirut bombing.

But even as Brahimi went into a meeting with Foreign Minister Walid Muallem in Damascus, fighting raged on northern battlefields, where regime jets resumed bombarding the key town of Maaret al-Numan which rebels captured on October 9.

Syrian warplanes resumed bombarding the key northwestern town of Maaret al-Numan on Saturday, as clashes erupted on a nearby highway and an explosion rocked a town in Damascus province, a watchdog said.

The warplanes pounded Maaret al-Numan as they have daily since it was overrun by rebels on October 9, the Syrian Observatory for Human Rights said.

Peace envoy Lakhdar Brahimi on Saturday will press Syrian officials for a truce, just hours after Lebanese politicians blamed Damascus for the killing of a top security official.

But even as Brahimi arrived in the war-torn country Friday, government jets hammered the rebel-held town of Maaret al-Numan in the northwest, and fighters there accused the regime of using cluster bombs in the attack, echoing claims by one rights group.

The Syrian National Council accused on Friday the “criminal regime” of Syrian President Bashar Assad of assassinating Internal Security Forces Intelligence Bureau head Brigadier General Wissam al-Hasan.

It said in a statement: “We know very well those who are behind these criminal acts and for whom they are being done for.”

Syria condemned on Friday the car bombing that left eight people dead and 78 others wounded in the Beirut district of Ashrafiyeh, describing it as a cowardly terrorist act, state news agency SANA reported.

Syrian Information Minister Omran al-Zohbi was quoted as saying "these sort of terrorist, cowardly attacks are unjustifiable wherever they occur."

Seventeen Lebanese people were killed on Friday in an ambush by the Syrian army at the Lebanese-Syrian border, reported Voice of Lebanon radio (93.3).

It said that the Lebanese were killed when Syrian troops ambushed their bus as it was heading from Lebanon's al-Qaa region to Syria al-Jousseh.

U.N. and Arab League envoy Lakhdar Brahimi arrived on Friday in Damascus as he bids to secure a ceasefire in Syria's 19-month conflict, an AFP journalist said.

Brahimi was received at Damascus airport by Syria's deputy Foreign Minister, Faisal Muqdad, and was scheduled to meet Foreign Minister Walid Muallem on Saturday.

European leaders said Friday they are concerned by the increasing violence in Syria and want opposition groups there to cooperate to ensure a peaceful change of government.

The 27 EU leaders voiced "deep concern with the increasingly deteriorating situation," in a draft summit statement seen by AFP.

Turkey on Friday called for Syria's regime to immediately stop deadly aerial bombing of rebel targets and for the two sides to observe a truce ahead of the Eid al-Adha Muslim holiday next week.

"It is particularly important that the Syrian regime immediately stop and without conditions, the recent attacks against the population with planes and helicopters," Foreign Minister Ahmet Davutoglu told reporters in Ankara.

Syria's air force carried out raids on Friday morning against rebels besieging a major military base in the northwestern province of Idlib, said the Syrian Observatory for Human Rights.

"Military aircraft dropped bombs that targeted rebels camped near (the base at) Wadi Deif," concentrating their firepower on the villages of Talmans and Maashemsha, said the Britain-based monitoring group.