— A spate of sinister killings in the central city of Homs is fueling fears that the popular uprising in Syria could descend into a version of the sectarian strife that has long destabilized neighboring Iraq and Lebanon.

The violence erupted over the weekend at a time when attention was focused on the huge and overwhelmingly peaceful anti-government demonstrations staged in many other cities around the country, including the largest protests yet to take place in the capital, Damascus.

In Homs, the weekly protests also went ahead, but under a cloud of sectarian tensions between the majority Sunni residents of the town, who constitute the bulk of the protest movement in the majority Sunni country, and the minority Alawites, the Shiite sect to which President Bashar al-Assad and most members of his regime belong.

Confirming the details of what happened is difficult because press access to Syria has been limited and the city is so sharply polarized along sectarian lines that residents gave starkly contrasting accounts.

But based on interviews with witnesses on both sides of the divide and a medical worker who tracked the violence and collected the bodies, it appears that the tensions soared after a crowd of Alawites armed with sticks surrounded a mosque in a Sunni neighborhood shortly before the noontime prayers on Friday and began chanting anti-Sunni slogans.

Sunnis responded by abducting three Alawites and on Saturday, their bullet-ridden bodies were found dumped in a Sunni neighborhood of the city. Alawites went on a rampage, looting and burning Sunni shops. In the melee, at least three Sunnis were killed, including a 27-year-old woman who was gunned down when she stepped outside her home in a majority Alawite neighborhood. One activist said that six Sunnis were killed, bringing the total number of deaths in the tit-for-tat killings to nine, though the medical worker who saw the bodies could only confirm a total of six.

Residents on Monday described a city gripped by fear, with most shops closed, bursts of unexplained gunfire and Sunni and Alawite residents fleeing those areas in which they found themselves in the minority.

“It’s on the edge of civil war,” said a Christian businessman, who spoke on condition of anonymity because he feared for his safety. He said he originally supported the protest movement, but now stands with the government after witnessing incidents of sectarianism that make him fear for the future of Syria's religious minorities.

A democracy activist in Homs, who also did not want to be named for fear of repercussions, said Sunni opponents of the government are just as scared.

“The atmosphere in the city of Homs is horrible,” he said. “People are afraid of genocide and we pray the night passes without us being killed.”

This is not the first time that Homs, Syria’s third largest city with 1.5 million people, has witnessed sectarian violence since nationwide protests against Assad’s rule erupted in cities across the country four months ago. On several occasions, groups of Alawite youths have clashed with demonstrators during the regularly scheduled Friday protests, residents say.

Most of the estimated 1,400 deaths in the uprising so far have been protesters shot by security forces, and human rights groups say at least 30 were killedFriday. But with the Syrian unrest now entering its fifth month, and in the absence of any sign of compromise either by the government or the protesters, the danger that the standoff will escalate into a wider sectarian conflict is real, analysts say.

The Syrian government has long blamed almost all of the protests on what it calls “armed gangs,” and repeatedly warns that continued unrest could lead to civil war. Democracy activists accuse the government of promoting sectarian tensions in order to justify the brutal tactics used to suppress protests, and to dissuade the international community from backing the protesters’ demands for Assad’s fall.

“The games and dirty practices of the regime in order to incite a sectarian fight to divide the citizens of (Homs) won’t work,” said a statement issued by the Local Coordination Committees, the most organized of the activist groups, in response to the violence. “We reaffirm the peaceful nature of the revolution.”

But there have been several indicators that the Local Coordination Committees, one of several groups involved in organizing and monitoring protests, do not exert full control over the protesters in Homs, or even in many other towns around the country.

A Facebook page that appeared last week, entitled Homs Revolution and featuring a picture of a masked man, offers one glimpse into the depth of the sectarian hatreds that are surfacing. Postings refer to Alawites as “pigs,” describe a plot by “nusariya” — a derogatory term for religious minorities — to purge Syria of Sunnis and urge Sunnis to take up arms against the government. The origins of the page, which has more than 2,000 “likes,” cannot be confirmed.