A spokesman for U.N. High Commissioner for Human Rights said the global body has received unconfirmed reports of “a particularly grizzly set of summary executions” in the Baba Amr neighborhood of Homs on Thursday.
He said the U.N. is appealing to authorities to prevent unlawful reprisals, torture and arbitrary detentions.
Syrian government forces on Thursday gained control of Homs following a month-long military assault against opposition rebels.
The rebels, from the Baba Amr Revolutionary Brigades, said the “tactical retreat” reflected “worsening humanitarian conditions, a lack of food, medicine and water, electricity and communication cuts as well as shortages in weapons.”
Britain's Prime Minister David Cameron on Friday called for the Syrian government to be held accountable for crimes committed during its assault. During a summit of European leaders in Brussels, he said that no matter how long it takes, there will be a “day of reckoning” for what he called a “dreadful regime.”
An official with the Syrian Arab Red Crescent was quoted as saying that a convoy of seven trucks was on its way to Homs carrying medical supplies and other humanitarian aid.
The U.N. Security Council unanimously approved a statement “deploring” what it called the “rapidly deteriorating humanitarian situation” in areas affected by violence linked to Syria's year-long uprising against Mr. Assad's autocratic rule.
The Council also expressed “disappointment” that Syria has not allowed U.N. humanitarian coordinator Valerie Amos to visit the country despite repeated requests and intense diplomacy. The statement called on the Assad government to grant Amos and humanitarian workers “immediate and unhindered access” to all people affected by food shortages and a lack of medical care.
The Security Council statement is the world body's first action on the Syrian crisis. Council members Russia and China have twice vetoed resolutions that would have condemned the Syrian government for its deadly crackdown on the revolt.
In comments Friday, Russian President Vladimir Putin refused to speculate on the future of Mr. Assad's leadership, but said reforms in Syria were long overdue.
Meanwhile, two French journalists who were injured and trapped in Baba Amr for days were evacuated from the city and were to head back to France.
Freelance reporter Edith Bouvier and her photographer Williams Daniels suffered injuries when government shelling struck a makeshift media center where Western journalists were sheltering in Baba Amr last week. The attack killed two of her counterparts. Bouvier and Daniels had sneaked into Syria on assignment with the French newspaper Le Figaro. They were the last of the surviving journalists to escape the district.
The U.N. says more than 7,500 people have been killed since the revolt began last March. Syrian officials blame the uprising on foreign-backed armed “terrorists” who, the government says, have killed more than 2,000 security personnel.