International envoy Lakhdar Brahimi was set to meet with Syrian President Bashar al-Assad in Damascus on Saturday, hoping to breathe life into stalled peace efforts, as fighting rages in Damascus and beyond.

On Friday Brahimi met Syrian opposition figures who said he was bringing 'new ideas' to the peace effort, as blasts rocked Damascus and regime air strikes targeted rebel areas in Aleppo.

Brahimi held talks with opposition groups tolerated by Assad's regime such as the National Coordination Committee for Democratic Change, which groups Arab nationalists, Kurds and socialists.

"We told Mr Brahimi... of our support for his efforts to resolve the crisis by ending the violence and killings, providing medical care and releasing political prisoners," Hassan Abdel Azim, the bloc spokesman, told reporters.

"Mr Brahimi will listen to the opposition and officials and crystalise new ideas and a plan that could succeed," he said after their talks in a Damascus hotel, adding that the peace initiative of his predecessor Kofi Annan would be amended.

"There will be new ideas and measures," Abdel Azim told reporters.

He said a delegation of his group would leave on Saturday for China, a key Damascus ally, to urge Beijing to 'put pressure on the regime to stop the violence, free detainees and allow peaceful protests'.

Brahimi 'will meet the Syrian president in the morning' on Saturday, United Nations spokeswoman Vannina Maestracci said, adding that the international peace envoy would also hold talks with Arab ambassadors and a European Union delegation.

Brahimi is on his first Damascus visit since his appointment to replace Annan who quit the post after a hard-sought peace deal he brokered became a dead letter.

Brahimi said on arrival on Thursday that the conflict was deteriorating.

"We came to Syria to hold meetings with our Syrian brothers because there is a big crisis, and I think it is getting worse," the Algerian veteran troubleshooter said, quoted by Syria's official SANA news agency.

Brahimi also met Foreign Minister Walid Muallem Friday.

Muallem assured him of 'Syria's full cooperation' and stressed that any initiative must be based on "the interests of the Syrian people and their freedom of choice without foreign intervention," SANA reported.

Fighting raged in several areas on Friday.

Regime forces used fighter jets and helicopter gunships to pound the northern city of Aleppo and the province of the same name, where fierce clashes also raged around a military airport, monitors said.

Warplanes bombarded the rebel-held towns of Al-Bab and Marea near Aleppo city, said the Syrian Observatory for Human Rights, adding that army forces and rebels fought around Minnigh military airport.

Despite shelling by regime forces, as seen in videos posted online, residents of Marea, Aleppo city and towns across the northern province came out for anti-regime demonstrations after the weekly Muslim prayers, activists said.

Protests were also reported in the provinces of Damascus, Idlib, Daraa in the south and Hama in central Syria, the Observatory said, adding that soldiers used 'explosive devices' against protesters in Hama city, wounding several people.

It said the army also stormed the Sayyida Zeinab district of southeast Damascus province, making several arrests.

Pope says arms imports must stop

In the central Aleppo district of Midan, regime forces launched air strikes on two rebel-held police stations, according to Observatory director Rami Abdel Rahman.

In the Hanano district of northeast Aleppo, air strikes destroyed another police station in rebel hands, Abdel Rahman said.

Near the capital, at least 15 soldiers were killed or wounded in an attack on their vehicle in the town of Douma, where clashes broke out near the municipal building, according to the Observatory.

In Damascus itself, three large explosions were heard in the late morning Friday, an AFP reporter said.

The Britain-based Observatory said 65 people were killed in all on Friday -- 49 civilians, 13 soldiers and three rebels.

It estimates that more than 27,000 people have been killed since the uprising against Assad's rule erupted in March last year. The United Nations puts the toll at 20,000.

In neighbouring Lebanon, Pope Benedict XVI on Friday started a weekend visit with a call for an end to arms imports to Syria. "Arms imports must stop once and for all, because without arms imports, war cannot continue," he told reporters.

Hollywood movie star Angelina Jolie, meanwhile, expressed concern about the threat of a winter freeze to Syrian refugees who have fled the conflict, a day after meeting refugees at camps in Turkey.

"With the violence in the conflict showing no signs of easing up and the numbers (of refugees) growing... it is a very large concern for all of us," Jolie, a UN special envoy, told reporters in Ankara.

"I share everyone's concern about the winter approaching," she added, calling for help to make sure that "nobody freezes to death in this very very frightened time."