Troops killed more than 20 people Sunday in a blistering raid on a central village, a watchdog said, while twin blasts rocked Damascus and a town near Syria's second city Aleppo was hit by air strikes.
As the violence raged, new international peace envoy Lakhdar Brahimi said change in Syria was "unavoidable," although he carefully refrained from calling for President Bashar al-Assad to step down, as his predecessor Kofi Annan had.
Jihad Makdissi, a spokesman for Assad's embattled government, announced Brahimi would "soon" travel to Damascus, expressing confidence that "he will listen to us."
The Syrian Observatory for Human Rights said it expected the death toll to mount from the army offensive on Al-Fan village in Hama province, one of the main arenas of conflict in the more than 17-month uprising.
The Britain-based watchdog had no details on whether those killed were civilians or rebel fighters, "but all 21 of the dead were men," said its director Rami Abdel Rahman.
Horrific images shot and posted on YouTube by activists in Al-Fan showed a long row of bodies shrouded in white cloths, laid out on the ground surrounded by scores of weeping men, women and children.
State news agency SANA said all of those killed during the Al-Fan clashes were from "an armed terrorist group that was attacking citizens and security forces."
They were among at least 103 people killed in violence across the country on Sunday, including 66 civilians, according to the latest Observatory figures.
In Damascus, twin bombs exploded near a tightly guarded government compound in the heart of the capital, wounding four people a day after a bombing killed 15 people in the city's south, state television said.
The latest bombings struck in Abu Remmaneh district where security buildings and the office of Vice President Faruq al-Shara are located, the television said, blaming "terrorists."
Shara is the highest-ranking Sunni Muslim in Assad's minority Alawite-led government and was the subject of repeated defection rumours last month before he made a public appearance during a visit by a senior envoy from key ally Iran.
The Ahfad al-Rasul (Grandchildren of the Prophet) brigade of the rebel Free Syrian Army claimed responsibility for the attack, also threatening to target Assad's palace.
Near Aleppo, another key battleground in the conflict, an AFP correspondent said air strikes were carried out on a residential area of Al-Bab, a rebel rear base north of the commercial hub.
"The plane circled and circled and circled before it dropped the bomb," said Ahmed, a resident of the town which is periodically targeted. He pointed out fragments of vehicles protruding out of the debris.
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Columns of smoke rose from the entrance to Aleppo itself, where fighting was reported to have been limited to a handful of neighbourhoods of the city, scene of fierce fighting since July 20.
Elsewhere, shelling of Qusayr destroyed the last working bakery in the rebel-held part of the central town, activists said, aggravating a growing food shortage.
Rights watchdogs have expressed growing concern about deteriorating conditions in areas under a protracted army siege, including parts of Aleppo and third city Homs.
"The shelling of Hanano did not stop from midnight until 5:00 am," an activist told AFP from the pro-opposition northeastern district of Aleppo.
Brahimi, who took over as international peace envoy on Saturday, told Al-Jazeera that "change is necessary, indispensable, unavoidable."
He said his position was to engage all the parties and he would not be drawn on Assad's future.
"It is too early to speak about who should go and who should stay," he told the channel.
"This is not a step backwards. Mr Assad is there and is the president of the present government," he said. "Kofi talked to him, and I will talk to him."
Similar comments by the veteran Algerian diplomat soon after his nomination last month drew an angry reaction from Syria's exiled opposition, which accused him of giving Assad's regime a "licence to kill."
Brahimi, who will formally take the reins in handover ceremony with Annan and UN chief Ban Ki-moon on Tuesday, has been holding meetings at the UN headquarters in New York.
He takes over amid mounting pessimism about the prospects for peace after Annan announced he was stepping down last month, blaming divisions in the international community for the failure of his April six-point peace plan.
The violence has since intensified with August marking the bloodiest month in the uprising, costing 5,440 lives including 1,248 last week alone, according to the Observatory, taking its overall toll for the conflict to 26,283 dead.
In an interview with a Lebanese television station, Syria's foreign ministry spokesman Makdissi said Brahimi would "soon" make a visit to Damascus.
"We will listen to him and he will listen to us," Makdissi told NBN channel, a pro-Damascus network.
"The issue is not personal, and has nothing to do with the envoy," said Makdissi.
"We tried Mr Kofi Annan. And all the reasons that led to his initiative's unhappy ending were not Syrian," he said, blaming "powerful UN Security Council members (for) discouraging dialogue."