UN-Arab League envoy Lakhdar Brahimi on Sunday kept up his regional push for peace talks on Syria, where a suicide car bombing and assault on a key Damascus checkpoint killed 16 Syrian soldiers.
Brahimi met with Egypt's foreign minister Saturday, saying "intense efforts" were under way to convene a Syrian peace conference in Geneva next month.
Syrian state media blamed "terrorists" for a bombing at the entrance to the mixed Christian-Druze Damascus suburb of Jaramana.
The Syrian Observatory for Human Rights said a suicide bomber from the Al-Qaeda-linked Al-Nusra Front detonated an explosives-packed car at the checkpoint between Jaramana and rebel-held Mleha.
Fighting raged for much of Saturday, with rebel mortar fire hitting Jaramana and regime aircraft striking back, according to the Britain-based Observatory, which relies on activists and medics on the ground.
At least 16 soldiers and 15 jihadists were killed, it said.
One resident said the fighting was "unprecedented" since Syria's conflict erupted in March 2011, telling AFP by telephone: "It is very violent. We can hear automatic weapons fire, mortar rounds, bombardments."
The conflict, which erupted after President Bashar al-Assad launched a bloody crackdown on Arab Spring-inspired democracy protests, is believed to have killed more than 115,000 people.
Millions more have been forced to flee the country and hundreds of thousands are trapped by the fighting.
UN humanitarian chief Valerie Amos on Saturday called for a ceasefire in the Damascus suburb of Moadamiyet al-Sham, where thousands of people were evacuated last week and where she said "the same number or more remain trapped."
The founder of the Syrian Observatory for Human Rights, living in exile in Britain, told AFP it published the grim toll of the civil war to draw the world's attention to the "endless bloodbath".
"Our objective is to release the truth about what is happening in Syria. We document, we verify and we report," said Rami Abdel Rahman, adding: "Our only agenda is defending human rights and reaching a democratic state."
In another sign of Syria's growing misery, the World Health Organisation said it had detected two possible cases of polio in the eastern Deir Ezzor province which, if confirmed, would be the country's first known cases since 1999.
Envoy heads next to Syria, Iran
Meanwhile, nine Lebanese Shiite pilgrims seized by Syrian rebels 17 months ago and two Turkish Airlines pilots kidnapped in Beirut in August arrived back home late Saturday under an exchange deal mediated by Turkey and Qatar.
And at the United Nations Arab ambassadors called on Saudi Arabia to rethink its decision to reject a seat on the Security Council in protest over its handling of the Syrian conflict.
They said it was crucial for Saudi Arabia to represent the Arab and Muslim world on the council "at this important and historical stage, specifically for the Middle East region."
Brahimi, the joint envoy of the UN and the Arab League, is to meet with the head of the pan-Arab group on Sunday and then head for talks in Syria itself and Iran, a key backer of the Assad regime.
But prospects for a peace conference remain dim, with Syria's opposition divided and due to vote next week on whether to take part, and Assad's government insisting he will not bow to the rebels' chief demand and step down.
The push for the Geneva talks will also be high on the agenda of US Secretary of State John Kerry, who heads to Europe to attend a "Friends of Syria" meeting in Britain on Tuesday.
The renewed push for peace talks comes after Damascus accepted in September a US-Russian deal to hand over its chemical arsenal for destruction.
But the political opposition remains divided amid recent clashes between mainstream fighters and jihadists, as well as growing rifts between rebels fighting on the ground and the external opposition.
The main National Coalition opposition bloc said members will decide next week whether to attend the Geneva talks, while the Syrian National Council, a coalition member, has threatened to quit if they do.
The nine Lebanese Shiite pilgrims, who were kidnapped by Syrian rebels last year as they were returning from visiting holy sites in Iran, were welcomed home in Beirut late Saturday.
The Turkish pilots, seized in Lebanon to push Turkey to put pressure on the Syrian rebels it supports to release the pilgrims, were freed and returned to Istanbul.
Syrian rebels also had demanded the release of some 200 prisoners from Syrian jails in exchange for freeing the pilgrims. It was not immediately clear if those releases went ahead.