AMMAN: Syrian troops bombarded a town near Damascus on Thursday and fighting raged in and around the northern city of Aleppo, a day before a proposed truce for a four-day Muslim religious holiday.

President Bashar al-Assad's government was expected to make a statement later in the day on whether it accepts the temporary ceasefire advocated by U.N.-Arab League envoy Lakhdar Brahimi.

The Syrian authorities said on Wednesday they were still studying the plan, but Russia's envoy to the United Nations said Damascus had indicated to Moscow that it would agree to it.

China urged all sides to respect a ceasefire, an idea also backed by Syria's main regional ally Iran, but there was no sign on the ground of any let-up in the violence on the eve of Eid al-Adha, the biggest feast on the Muslim religious calendar.

Syrian troops pounded Harasta, near Damascus, with tank and rocket fire, killing five people, after rebels overran two army roadblocks on the edge of the town, on the main highway from the capital to the north, opposition campaigners said.

Rebels tried to maintain pressure on two army bases on main roads leading to the contested city of Aleppo, a key prize in the 19-month-old uprising against Assad's authoritarian rule.

"No one is taking the ceasefire seriously," said Moaz al-Shami, an opposition activist in Damascus.

"How can there be a ceasefire with tanks roaming the streets, roadblocks every few hundred metres and the army having no qualms about hitting civilian neighbourhoods with heavy artillery? This is a regime that has lost all credibility."

Even if Assad accepts a truce, there may be no unified response from Syria's fractured opposition. Some armed groups have said they will abide by a ceasefire. Others, including the Islamist militant Al Nusra Front, have rejected it.

In Aleppo, where opposition activists reported more fighting and shelling, the rebel Shining Aleppo Division said it would observe the ceasefire despite "doubts over the credibility of the regime" if Assad stopped moving armoured units, halted air raids and released thousands of prisoners held without trial.

Brahimi's predecessor, former U.N. chief Kofi Annan, declared a ceasefire in Syria on April 12, but it soon became a dead letter, along with the rest of his six-point peace plan.

Violence has intensified since then, with daily death tolls compiled by opposition monitoring groups often exceeding 200.

"Harasta is being pummelled by tanks and rocket launchers deployed on the highway. The rebels are putting up a fight and it does not seem the army will be able to enter the town this time," said a Damascus resident, who gave his name as Mohammed.

Assad's force pushed into Harasta a month ago in an operation which opposition activists said killed 70 people.

In Geneva, U.N. war crimes investigators said they had asked to meet Assad to seek access for their team, which has been excluded from Syria since it began work a year ago. There was no word on how the Syrian leader would respond.

The inquiry led by Brazilian expert Paulo Pinheiro has been investigating atrocities by both sides in the conflict

In their latest report in August, the investigators said that Syrian government forces and allied militia had committed war crimes including murder and torture of civilians in what appeared to be a state-directed policy.

In Harasta, an opposition group described the town as a "disaster zone" after the shelling. "An (army) roadblock had been set up next to the main bakery. There is no water, no food, no medicine and prolonged power cuts," it said in a statement.

Activists also reported army artillery on the town of Anadan northwest of Aleppo. To the southwest of the city, rebels have been surrounding army barracks at the town of Orum al-Sughra, on the road between Aleppo and the Turkish border.

Assad's forces appear to have curbed a two-week-old rebel offensive against an army base at Wadi al-Deif to the south, near Maarat al-Numaan on the Aleppo-Damascus highway.

Rebel commanders said an armoured column sent to defend the base 10 days ago had arrived near Maarat al-Numaan despite rebel attacks. The column, now deployed just south for the town, is bombarding rebel forces operating near Wadi al-Deif.