At least 20 people were killed in renewed shelling by Syrian troops Thursday, opposition activists said, hours before Arab League foreign ministers were to discuss the status of a UN-brokered peace plan, dpa reported.
The military bombarded Douma in suburban Damascus and the eastern city of Deir al-Zour, activists said. Explosions and heavy gunfire were heard in Harasta near the capital, as security forces made mass arrests, said the opposition.
Heavy clashes were also reported between army troops and opposition rebels in the southern province of Daraa. There were no immediate reports of casualties.
The persistent violence has raised fresh doubts about the durability of the two-week ceasefire, a key element of the peace plan proposed by United Nations-Arab League envoy Kofi Annan.
Meanwhile, the key opposition Syrian National Council (SNC) called for a meeting of the UN Security Council on the alleged killing of 70 civilians by government forces Wednesday in the central province of Hama.
"Those victims were on their way to meet with UN observers when a rocket was fired on their area," SNC member Naji Tayarra told dpa.
Activists in the area said at least three rockets hit houses in the Masha al-Tayyar district of southern Hama, and the victims included 13 children.
But state-run news agency SANA reported that a bomb had exploded in Hama while "terrorists" were preparing to attack government soldiers. It said 16 people were killed.
Russia, a main ally and arms supplier to Syria, has accused the opposition of violating the ceasefire.
"Opposition groups have essentially reverted to waging wide-scale terror in the region," said Russian Foreign Ministry spokesman Alexander Lukashevich.
Arab League foreign ministers were to meet later Thursday in Cairo, and would assess the Syrian government's compliance with Annan's plan to end more than a year of bloodshed, Egyptian state-run Al Ahram newspaper reported.
In Brussels, Lebanese Prime Minister Najib Mikati said his country was determined to stay out of the unrest in neighbouring Syria. Lebanon shares 80 per cent of its borders with Syria.
"The most important (thing) is to create stability in Lebanon for the time being," Mikati said. "My position is to disassociate from Syria ... because of the kind of particularities that we have with Syrian historic relations."
Syria had troops stationed in Lebanon until 2005. Lebanese society is already divided, with the Shiite movement Hezbollah loyal to the regime in Damascus and others backing the uprising against President Bashar al-Assad's regime.