DAMASCUS: Hopes of a truce being implemented in war-torn Syria during this week's Muslim Eid holidays are "slim," the Arab League said on Monday, as heavy fighting erupted in Damascus and on northern battlefields.

But the UN held on to the hope that warring sides in Syria will observe a truce during the four-day Eid al-Adha holiday which begins on Friday, saying it had plans to assemble a peacekeeping force if a ceasefire takes hold.

"We are getting ourselves ready to act if it is necessary and a mandate is approved," UN peacekeeping chief Herve Ladsous told reporters in New York.

He warned, however, that the plans were tentative while fighting rages, and would need the approval of the 15-nation Security Council which has been divided on the conflict.

UN-Arab League peace envoy Lakhdar Brahimi had on Sunday indicated a favourable response to his appeal to both sides of the Syrian conflict to observe a truce during Eid al-Adha.

Arab League deputy secretary general Ahmed Ben Helli dashed those hopes on Monday.

"Unfortunately, hope for implementing the truce during Eid al-Adha is slim so far," Ben Helli told AFP on the sidelines of the World Energy Forum in Dubai.

"The signs, both on the ground and by the government... do not point to the presence of any real will" to implement a ceasefire, he said.

Fighting raged on Monday in Syria, including around Damascus, the northern city of Aleppo and the rebel-held town of Maaret al-Numan in the northwest province of Idlib.

The Syrian Observatory for Human Rights said at least 84 people, including 22 civilians, were killed, adding to a toll of more than 34,000 people the group says have been killed since an anti-regime revolt erupted last year.

Brahimi said a temporary truce could be the first step to more permanent peace.

"This is a call to every Syrian, on the street, in the village, fighting in the regular army and its opponents, for them to take a unilateral decision to stop hostilities," he said on Sunday.

Brahimi said he contacted political opposition leaders inside and outside Syria and armed groups in the country and "found them to be very favourable" to the idea of a truce.

President Bashar al-Assad met Brahimi on Sunday and said he was "open to any sincere efforts seeking to find a political solution to the crisis based on respecting Syria's sovereignty and rejecting any foreign interference."

Pitched battles near Maaret al-Numan

As they met a bomb attack on Bab Touma, the main Christian quarter of Damascus, killed 13 people and triggered the anger of Assad's ruling party's mouthpiece, Al-Baath newspaper.

"Armed terrorist groups responded to Brahimi's (ceasefire) appeal with a series of explosions in Damascus, including a suicide bombing in Bab Touma, leaving dozens dead or wounded," it said.

On the ground, there was no sign on Monday of a let-up in the violence.

The Observatory said clashes erupted in the morning when troops tried to storm the rebel-controlled town of Harasta on the northeastern outskirts of Damascus.

Soldiers and rebels also fought pitched battles near Maaret al-Numan, which rebels seized on October 9, and around an army base in nearby Wadi Daif, in Idlib province, said the watchdog.

The clashes were the fiercest seen yet around the Wadi Daif base, which has been besieged for nearly two weeks by rebels, it said, adding that a nearby checkpoint was in flames after rebels attacked it.

Maaret al-Numan lies along the Aleppo-Damascus highway which serves as a key army supply route.

Fierce machinegun battles also erupted near Aleppo's ancient Umayyad Mosque, as troops fended off rebel attacks on checkpoints, said a military source, adding: "Until now we have kept them at bay, but this is a large attack."

State news agency SANA reported that "terrorists" abducted general prosecutor Tayssir Smadi in the southern town of Daraa. The Observatory confirmed the report and said gunmen also kidnapped Baath Party member Mahmud Akrad.

And in Lebanon fresh sectarian fighting erupted on Monday between opponents and supporters of the Syrian regime after Friday's killing of a top security official in a massive Beirut car bombing blamed on the Damascus government.

On the Jordan border, a Jordanian soldier was killed before dawn in a clash with militants trying to cross into Syria, Amman's information minister Samih Maaytah told AFP.

Brahimi has warned that the 19-month Syria conflict could spill over and set the region ablaze if no solution is found.