Syrian troops reasserted control Monday of rebellious suburbs outside Damascus, retaking some districts amid stiff resistance as the opposition reported dozens killed in fierce fighting.
Armed rebels were falling back to avoid the government's onslaught, said opposition activists, as regime tanks and troops pulled into rebel bastions near the capital.
"We've entered the stage of street war," said an opposition activist in the Damascus suburb of Duma, who asked not to be named for security reasons. "Today, one side is gaining control, tomorrow the other side. Today, the regime is in control."
The increase in violence came as diplomats at the United Nations prepared to debate Syria's future.
On Tuesday, the U.N. is scheduled to consider an Arab League plan, backed by Western nations, that calls for Syrian President Bashar Assad to relinquish power as part of a transition to a unity government and the holding of new elections. The Syrian government has condemned the blueprint as an affront to its sovereignty.
Russia, a Syrian ally and major arms supplier to the Assad government, has indicated it would veto any U.N. resolution backing a change in leadership, economic sanctions or an arms embargo against Syria.
On Monday, Russia called for all sides in the Syrian conflict to participate in talks in Moscow. Many opposition activists have said the time for discussions with Assad is over.
Syrian troops seeking to impose control on Damascus' suburbs were reported to have entered the towns of Hammouriya and Kfar Batna, among other areas. According to opposition activists, the troops failed to advance deep into Saqba, which has been in rebel hands.
One opposition activist in the besieged mountain town of Rankous said troops stormed the town after days of shelling, though most of the rebels and many residents had already fled.
"The Syrian army will not be able to maintain the area for long," said the activist. "They will be an easy target for us."
The recent fighting reflects the kind of guerrilla warfare that has now engulfed major swaths of Syria.
The opposition says its armed ranks are growing daily, bolstered by defections from the military. In classic guerrilla fashion, rebels appear able to infiltrate Syrian towns and neighborhoods when the military presence is relatively low, then slip away once reinforcements arrive.
The antigovernment protests that were a signature feature of the Syrian uprising continue. But it seems clear that the government now faces an armed insurgency — by what the regime calls "terrorists" and "armed groups."
The official Syrian state news service daily cites ambushes, acts of sabotage, roadside bombs and group burials of security personnel killed in fighting. Reports have circulated that the army is over-stretched because of a plethora of battle fronts.
An opposition coalition, the Local Coordination Committees, reported 95 more deaths Monday throughout Syria. Most were in the troubled province of Homs, a hotbed of the rebellion, where heavy shelling and gunfire were reported, especially in the city of Rastan.
More than 300 people have been killed nationwide in the last five days, according to the Local Coordination Committees, making it one of the deadliest stretches since the rebellion broke out 10 months ago.
There was no way to verify the numbers, since much of Syria is closed off to the international media.
The United Nations says more than 5,000 people have died in the violence since March. According to the government, more than 2,000 security personnel have been killed.
The escalating violence prompted the Arab League to suspend the work of about 100 league monitors in Syria. They had been tasked with ensuring that the government complied with the terms of an Arab League-negotiated peace plan that, among other things, calls for the withdrawal of the military from cities and residential areas.
Marrouch is a special correspondent.