The death toll in the Syrian uprising has soared to at least 3,500 people, the United Nations said Tuesday, a sobering measure of the scope of a military crackdown that has bloodied city after city but failed to crush the 8-month-old revolt against President Bashar Assad's regime.
Under the strain of daily killings, some Syrians see a dangerous fracturing of society as long-festering resentments over religion, sectarian identity and poverty bubble to the surface. Moreover, there were new signs that an uprising that has so far been largely unarmed is increasingly starting to fight back, threatening a rise in the bloodshed.
The dangers have been on display this week in the country's third-largest city, Homs. This week, security forces have been besieging the city for the third time this year to stamp out what has been epicenter of the revolt.
Most notably this time, dissident troops have been putting up a stiff defense as security forces blast their way into rebellious neighborhoods. Amid the fighting, there have been tit-for-tat sectarian killings suspected to be between Sunni Muslims, who largely back the protests, and Alawites, a Shiite sect that makes up the backbone of Assad's regime.
In Geneva, a spokeswoman for the U.N. High Commissioner for Human Rights said the count of 3,500 dead throughout the uprising was likely a conservative figure.
"We are deeply concerned about the situation and by the government's failure to take heed of international and regional calls for an end to the bloodshed," said Ravina Shamdasani.
She told The Associated Press the new death toll comes from a variety of credible sources on the ground both within and outside Syria that are then corroborated by the U.N. human rights office.
Syria has seen the bloodiest crackdown against the Arab Spring's eruption of protests. Deaths in Egypt, Tunisia and Yemen have numbered in the hundreds. Libya's toll is unknown and likely higher than Syria's, but the conflict differed there: Early on it became an outright civil war between two armed sides.
Syria, in contrast, has developed into a murderous grind. Though internationally isolated, Assad appears to have a firm grip on power with the loyalty of most of the armed forces, which in the past months have moved from city to city to put down uprisings. In each place, however, protests have resumed.
In Homs, one of Syria's most diverse cities with a population of about a million people, security forces have been assaulting Sunni-majority districts that have been the center of protests, raiding homes and fighting dissident troops _ particularly in the neighborhood of Baba Amr. At least 110 people have been killed in Homs the past week, according to activists, 40 of them from Baba Amr.
Electricity, water and phone lines have been cut to the restive neighborhood, where a man and a woman were killed by security forces' fire on Tuesday, according to activist Salim al-Homsi.
"There are mountains of garbage everywhere," al-Homsi said. "It is difficult to bring in medical equipment, bread and heating fuel. There is a shortage of everything."
Amateur video posted online Tuesday showed a small group of alleged military defectors from the group known as the Syrian Free army driving through Baba Amr on Monday with automatic rifles and shoulder-carried RPGs.
"We are here to protect the peaceful, unarmed protesters in Baba Amr," said a soldier who identified himself as a member of the Al-Farouk brigade. "We will teach them a hard lesson," he said of the attacking forces.
Still, on Tuesday, regime forces controlled large parts of the district after defectors pulled back, said al-Homsi.
The government has largely sealed off the country from foreign journalists and prevented independent reporting, making it difficult to confirm events on the ground. Key sources of information are amateur videos posted online and details gathered by witnesses and activist groups who then contact the media, often at great personal risk.
It is difficult to gauge how many people have defected from the army and what kind of threat they pose to the regime. To be sure, the security forces are overextended, exhausted and underpaid.
But Assad, and his father who ruled Syria before him, stacked key security and military posts with members of their minority Alawite sect over the past 40 years, ensuring loyalty by melding the fate of the army and the regime.
The power structure means the army will protect the regime at all costs, for fear they will be persecuted if the country's Sunni majority gains the upper hand. Most of the army defectors, at least so far, appear to be lower-level Sunni conscripts.
Still, the crackdown is exacerbating long-standing sectarian resentments in Syria, in Homs in particular.
A predominantly Sunni city 100 miles (160 kilometers) north of the capital, Damascus, Homs also has a mix of Alawites and Christians, both of which generally support the regime. The communities have lived side-by-side _ however uneasily at times _ for decades, but last week there was an explosion of sectarian reprisal killings that killed scores of people, activists say.
"People who have lived in the same area for years without problems now look at each other with suspicion," an activist in Homs told The Associated Press by telephone. "There is distrust now because there is fear."
The activist, like many people who spoke to the AP, asked that his name not be published out of fear for his safety.
Syria blames the bloodshed on "armed gangs" and extremists acting out a foreign agenda to destabilize the regime.
Sectarian warfare would be the worst-case scenario in Syria, evoking painful memories of the worst days of the Iraq war. The Syrian regime's supporters have exploited those fears by portraying Assad as the only force that can guarantee law and order. The protesters have been careful to portray their movement as free of any sectarian overtones.
Homs has shown sympathy for the opposition since the early days of the uprising. In April, protesters brought mattresses, food and water to the central Clock Square in Homs, hoping to re-create the mood of Cairo's Tahrir Square. But security forces quickly raided the encampment, a move that only increased the intensity of the protests. In July, security forces moved in again in a major siege.
The latest violence began a day after Damascus agreed to a peace plan brokered by the Arab League last week. The 22-nation body has scheduled emergency meeting for Saturday to discuss Damascus' failure to abide by its commitments to pull tanks and other armor out of cities and stop the bloodshed.
AP writer John Heilprin contributed to this report from Geneva.