A car bomb rocked the funeral of two government loyalists in a Damascus suburb killing 27 people on Tuesday as the army kept up its bombardment of rebel strongholds in the east of the capital.
The bombing hit Jaramana, a mainly Druze and Christian town on the southeastern outskirts of Damascus that the Syrian Observatory for Human Rights described as generally supportive of the government of President Bashar al-Assad.
"The number of people killed in a funeral held for two supporters of the regime has risen to 27," said the Observatory.
Earlier, state television had put the toll at 12, adding that another 48 were wounded.
"At around 3:00 pm (1200 GMT), a funeral procession was making its way to the cemetery, when a car parked on the side of the road exploded," an army official told AFP.
The funeral was held for two supporters of Assad who were killed in a bomb attack on Monday, the Britain-based Observatory said.
The force of the explosion completely demolished the facade of one building and caused heavy damage to others nearby, an AFP photographer reported.
State media blamed rebel fighters for the bombing, which came amid an intensified bombardment by government troops of eastern districts of Damascus that shelter some of the Free Syrian Army's best organised battalions.
But the opposition Syrian National Council accused Assad's regime of staging the bombing against its own supporters in a bid to divert attention from the killings of hundreds of people during an army assault on a largely Sunni Muslim suburb of the capital last week.
"The regime wants to cover up for its massacres," SNC spokesman George Sabra said, alluding to the discovery of more than 300 bodies in the town of Daraya that sparked an international outcry.
"It also wants to punish residents of Jaramana -- who are of mixed religious backgrounds -- for welcoming people who were displaced from nearby towns." Sabra told AFP by telephone.
"It wants to turn the revolution... into a bloody civil war fought along sectarian lines," he said.
Some 80 percent of Syrians are Sunni Muslim, while around 10 percent belong to Assad's Alawite community, five percent are Christian, three percent Druze and one percent Ismaili.
The opposition draws much of its support from the Sunni majority, who have borne the brunt of the government's crackdown.
Swedish Foreign Minister Carl Bildt warned Tuesday of the risks of Syria descending into bloody sectarian conflict after what he said was the inevitable fall of Assad's regime.
"Whether it will be replaced by a secular democracy, an Islamic one or by a sectarian fragmentation remains to be seen," Bildt said. "The longer the conflict lasts, the greater the risk that we will see the latter development."
The Observatory reported fierce shelling of northeastern neighbourhoods of Damascus as the army pressed its drive to push rebel fighters out of the capital.
Among the districts targeted was Qaboon where rebels from the Free Syrian Army claimed to have downed a military helicopter on Monday.
The rebels opened what they described as a new front in east Damascus at the weekend after a major offensive by the army last week against their positions southwest of the capital, including in Daraya.
Outside the capital, the army hit rebel positions in the second city Aleppo as well as in Idlib province, in the northwest close to the border with Turkey.
A bombardment of the Idlib village of Kfar Nabal killed at least 13 civilians, two of them women, among at least 97 people killed nationwide.
Activist network, the Syrian Revolution General Council, said warplanes had taken part in the assault and released gruesome footage of dozens of residents desperately combing the rubble of apartment blocks for survivors.
Rescuers were seen loading charred bodies onto the back of a truck in the footage which could not be independently verified.
Activists say around 25,000 people have been killed since the uprising against Assad's rule broke out in March last year, while the United Nations says more than 214,000 people have fled to neighbouring countries.
Underscoring the growing humanitarian crisis, it emerged that seven Syrians, two of them children, who attempted to flee the conflict by boat earlier this month, drowned off the coast of the nearby Mediterranean island of Cyprus.
The UN refugee agency said it was the "first case" of Syrian refugees trying to make the 100 kilometre (60 mile) sea passage.
"It is hard to know if this is a trend," UNHCR spokeswoman Melissa Fleming told reporters in Geneva.
She also said there had been a two-fold increase in arrivals in recent days at a refugee camp in Jordan, where officials reported more than 20 police injured on Tuesday in clashes with stonethrowing residents protesting about living conditions.
Syria's rebels meanwhile claimed that they had seized 10 missiles from the regime's arsenal in the eastern belt of Damascus province, amid a marked escalation of violence in the area.
Rebels calling themselves the Gathering of Ansar al-Islam (Partisans of Islam) Battalions posted footage on YouTube which they said showed a missile storage warehouse seized from regime troops.