Peace envoy Lakhdar Brahimi is pushing "extremely hard" for a ceasefire in Syria, his spokesman said on Tuesday as violence raged across the country and a warplane struck a queue for bread.

The Syrian Observatory for Human Rights said the unrelenting violence is dimming hopes for a ceasefire during the four-day Muslim Eid al-Adha holiday from Friday, as proposed by Brahimi.

"Neither the rebels nor the regime appear to want a ceasefire, and the daily death toll continues to exceed 100," Observatory director Rami Abdel Rahman told AFP.

The Observatory said 112 people were killed in Syria on Tuesday, including 10 people who died when a warplane bombed a bread queue in the northern city of Aleppo.

Brahimi's spokesman Martin Nesirky said the UN-Arab League envoy was pressing for a truce and would brief the divided UN Security Council on his efforts Wednesday.

"It remains to be seen what will happen" about the ceasefire, said Nesirky.

"Mr Brahimi is pushing extremely hard as is the secretary general because this is an extremely important moment."

The envoy, who was in Cairo on Tuesday after a visit to Syria, wanted "a long-lasting ceasefire that will enable a political process to unfold."

The 15-member Security Council is bitterly divided over the conflict with Western nations pressing for international actions against the regime of President Bashar al-Assad and Russia and China blocking these moves.

UN peacekeeping chief Herve Ladsous spoke on Monday of tentative plans top 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," said Ladsous.

The two sides to the conflict have given a cautious welcome to Brahimi's proposal but neither has committed itself to the plan for a ceasefire during Eid.

-- Assad makes Eid gesture --

Assad, in a pre-Eid gesture, issued an amnesty for all crimes committed in Syria "up until today," state television said.

But giving no quarter in the conflict that has cost more than 34,000 lives in the past 19 months, the deal excludes "terrorists" -- the regime's term for insurgents seeking to topple Assad and activists alike.

Damascus said, however, that Brahimi's visit which ended on Monday was "successful" although there was no concrete outcome.

The Syrian authorities "are still optimistic," deputy foreign minister Faisal Muqdad said. "The visit was successful and (Syria's) cooperation with Brahimi is without limits."

On the battlefront, warplanes raided an eastern district of Aleppo city, the conflict's focal point since mid-July, killing a child and nine other people, said the Observatory.

"Ten people, including a child, were killed by a military air strike near a bakery in the Masaken Hanano neighbourhood of Aleppo," Abdel Rahman told AFP. "It is always at the bread lines" where people get killed, he added.

A resident confirmed the aerial attack to AFP, saying civilians were killed "as they were standing in line to get bread from the Zahra bakery".

The Observatory also reported fighting in Damascus province, and said five children and three women were among 12 people killed in the district of Moadamiya by shelling that targeted a residential area.

Violence also gripped the eastern province of Deir Ezzor and Daraa in the south and warplanes pounded the northwestern town of Maaret al-Numan, which rebels seized on October 9.

Brahimi has 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.

However, the Arab League dampened hopes of a truce, saying the chances of it coming into effect were "slim."

Human Rights Watch accused Syria of stepping up the use of internationally banned cluster bombs despite denials of using them at all.

"Syria's denial is meaningless as evidence mounts that cluster bombs are raining down on towns and villages," said Steve Goose, HRW arms director.

Iran said it could host a "national dialogue" in the region among all the parties to the conflict.

Rebels reject any Iranian involvement, reflecting the view the US and some Western and Arab states hold that it is discredited by its unwavering support for Assad.

Iran, which accuses Western and Arab nations of arming the rebels, has repeatedly said it is in contact with opposition groups, without identifying them.