Fierce clashes erupted Wednesday after Syria’s regime sent reinforcements into rebel areas despite a truce pledge.
Syrian activists said there have been explosions and clashes across the country on Wednesday.
The surge in violence, which began even as Syrian officials claimed a pullout was underway, killed at least 74 people, mostly in northwestern Idlib province.
Opposition figure Mohammed Saleh told The Associated Press there has been a series of loud blasts in the central Homs region, and heavy machine gun fire in parts of the old city.
Activist Mohammed Saeed in the Damascus suburb of Duma told al-Arabiya that regime troops were carrying out raids and arrests on Wednesday. He said tanks and checkpoints remain in place.
Rights activists also charged Wednesday that the army is torching and looting rebel houses across the country in a campaign that could amount to crimes against humanity.
Dozens of armored personnel carriers arrived in Dael, a town in Deraa province where the uprising against Assad began in March 2011, as well as in Zabadani, a bastion of the rebellion near the border with Lebanon.
Clashes in the Atbaa area of Deraa left three civilians and two soldiers dead, activists told AFP.
In Idlib, heavy fighting took place on the outskirts of the town of Taftanaz, where scores of civilians, rebels and government soldiers were killed amid heavy machinegun fire and shelling, the Britain-based monitoring group said.
Earlier this week, UN-Arab League envoy Kofi Annan told the UN Security Council that President Bashar al-Assad had given assurances he would “immediately” start pulling back his forces and complete a military withdrawal from urban areas by April 10.
The United States accused Assad of failing to honor his pledged troop withdrawal.
Russia, however, said the Syrian government has informed Moscow that it has started implementing UN envoy Kofi Annan's six-point peace plan.
In Geneva, UN-Arab League peace envoy Kofi Annan's spokesman said an advance team from the United Nations' peacekeeping department will arrive in Damascus within 48 hours.
"A DPKO [Department of Peacekeeping Operations] planning mission should be arriving in Damascus within 48 hours," spokesman Ahmad Fawzi said.
As part of the six-point peace plan put forward by Annan to halt the violence, UN peacekeepers are planning for a ceasefire monitoring mission that would have 200 to 250 unarmed observers.
Doing so, however, require a Security Council resolution.