The increase of sectarian violence among warring sides in the Syrian conflict has heightened fears the brutal 11-month crackdown by the Assad regime on pro-democracy forces could see the country slide into an all-out civil war fanned by religious animosity.

“It is vital that all sides refrain from targeting people because of their ethnic or religious identity, and that every effort is made to avoid further civilian casualties,” said Rupert Colville, spokesman for the United Nations High Commissioner for Human Rights.

We have been warning since autumn about the danger of a full-blown civil war developing, said Colville, “with the distinct possibility of it becoming sectarian in nature.”

The growing sectarian polarization is between supporters of President Bashar-al-Assad, who comes from the minority Alawite sect, a branch of Shia Islam which comprises only 12 percent of the country's population ― but is strongly represented in the country's armed forces ― and Sunni Muslims, who represent about 75 percent of the population, and are firm supporters of the small Free Syrian Army.

Christian communities, which make up about five percent of the Syrian population, have remained largely on the sidelines during the armed hostilities.

Navi Pillay, U.N. High Commissioner for Human Rights, said on Feb. 13 that since the crackdown of anti-government protests began in March 2011, “security forces and government –supported Shabbiha militias have been responsible for  killing thousands of people through attacks on peaceful protests and in large-scale military operations in several cities.”

A senior U.N. diplomat, speaking on condition of non-attribution, said the sectarian situation in Syria is not black and white, noting the armed forces consist of both Sunnis and Alawites, while the opposition to Assad draws support from some Alawites, Christians, Druze, and others.

However, human rights groups say some areas, such as the city of Homs ― which is predominantly Sunni, though it includes Alawite and Christian neighborhoods ― have witnessed random kidnappings and a carnage of reprisal killings.

“In the Homs region there have been reports of targeting communities on religious grounds,” said Michel Nseir, program executive for the Middle East at the World Council of Churches (WCC).

“We have received some alarming reports of incidents of abuse by anti-government fighters, including kidnapping of security personnel and allegations of ill-treatment, torture and summary executions. However, so far, we have not been able to substantiate these reports ― though obviously we are taking them very seriously and will continue to seek to get verification,” said Colville.

He also suggested the presence and actions of armed anti-government fighters does not render the Syrian military’s indiscriminate attacks against civilian areas legal.

“Reports that al-Qaida may have been behind the recent series of deadly bomb attacks in Damascus and Aleppo are particularly worrying given that organization’s history of deliberately stoking sectarian hatred in both Iraq and Afghanistan,” Colville noted.

Nseir said churches in Syria can play a role in initiating dialogue, and mediating between the government and some opposition groups.

On Feb. 20, members of the executive committee of the WCC sent a pastoral message to the churches in Syria extending solidarity.

The International Committee of the Red Cross (ICRC) on Feb. 21 urged the Syrian authorities and all others involved in the ongoing violence to implement a daily cessation of fighting for at least two hours, in all areas affected, to allow the prompt delivery of humanitarian assistance.

“In Homs and in other affected areas, entire families have been stuck for days in their homes, unable to step outside to get bread, other food or water, or to obtain medical care,” said Jakob Kellenberger, ICRC president.