(Adds U.N. Security Council statement)
* Rebels leave Baba Amro after 26-day army siege
* Red Cross to enter district on Friday
* UN Human Rights Council condemns Syria
* Britain pulls diplomats out of Damascus
BEIRUT, March 1 Defeated Syrian rebels left their shattered stronghold in the city of Homs on Thursday after a bloody 26-day army siege aimed at crushing a symbol of the year-long revolt against President Bashar al-Assad.
Activists said a few fighters had stayed on in the Baba Amro district, which has endured weeks of shelling, sniper fire and privation, to cover their comrades' "tactical withdrawal". Soon afterward, the international Red Cross said Syrian authorities had finally given it permission to take aid into the district on Friday.
"The Free Syrian Army and all the other fighters have left Baba Amro," one activist said from Homs. "They pulled out."
A pro-government figure proclaimed that troops had "broken the back" of the rebellion and that the fall of Baba Amro heralded impending victory over a Western-backed insurgency.
A statement in the name of the fighters urged the International Committee of the Red Cross and other humanitarian groups to enter Baba Amro to protect and bring aid to 4,000 civilians who had stayed in their destroyed houses.
"We warn the regime against any retaliation against civilians and we hold it fully responsible for their safety," the statement said, adding that the rebels had been forced to leave because they were short of supplies and ammunition.
Russia and China joined other U.N. Security Council members in expressing disappointment at Syria's failure to allows U.N. humanitarian chief Valerie Amos to visit and urged that she be allowed in immediately, France said.
The ICRC said it had received a "green light" from the Syrian authorities to enter Baba Amro on Friday.
Reports from the city could not be verified immediately due to tight government restrictions on media operations in Syria.
One activist said Syrian soldiers had begun moving into Baba Amro from all directions after most of the fighters left and were hunting the rest. At least 17 rebels were put to death with knives after they were chased into nearby fields, he said.
Scattered gunfire could be heard inside Baba Amro and sporadic shelling hit nearby districts, the activists said. The overall level of combat exchanges seemed to have receded.
The drama in Homs unfolded without any immediate comment from Syrian officials or the state media, but Taleb Ibrahim, a Syrian analyst close to the government, said the military's operation in Homs had "broken the back of the armed groups".
"It's the beginning of Syria's final victory over the Qatari, Saudi, French, American and Zionist conspiracy against Syria," he told Lebanon's Hezbollah-run al-Manar television.
There was no immediate word on the fate of wounded French reporter Edith Bouvier and French photographer William Daniels, who had been among a group of journalists trapped in Baba Amro.
Two of these, American correspondent Marie Colvin and French photographer Remi Ochlik, were killed there in a bombardment a week ago. Two others later escaped into Lebanon.
Hundreds of civilians have been killed in Homs in the past month, activists say. Many of the wounded have received only rudimentary treatment in makeshift field hospitals.
Snow blanketed the city, where residents are short of food, fuel, power, water and telephone links, activists said.
Free Syrian Army commander Riad al-Asaad said the fight against Assad would go on until he fell: "The Free Army has left Baba Amro because of the brutal acts of the regime against civilians," Asaad, who is based in Turkey, told Al Jazeera.
President Assad, a London-trained eye doctor, is increasingly isolated in his struggle to crush an armed insurrection that now spearheads the revolt against four decades of his family's rule.
Britain said on Thursday it had withdrawn its diplomats from Damascus. Switzerland closed its embassy.
But the 46-year-old Syrian leader still has some allies.
Russia, China and Cuba voted against a resolution adopted overwhelmingly on Thursday by the Geneva-based U.N. Human Rights Council which condemned Syria for violations that it said may amount to crimes against humanity.
A Lebanese official close to Damascus said Assad's government was determined to regain control of Homs, Syria's third city, which straddles the main north-south highway.
"They want to take it, whatever happens, without restraint, whatever the cost," the official said, asking not to be named.
He said defeat for the rebels in Homs would leave the opposition without any major stronghold in Syria, easing the crisis for Assad, who remained confident he could survive.
Ayham Kamel, Middle East analyst with Eurasia Group, a political risk consultancy, said that if the fall of Baba Amro was confirmed, it would be a severe setback to Assad's foes.
"That sends a strong message to the opposition that the army has ample strength to dominate on the ground," he said.
"Baba Amro was a very significant base for the rebels ... a heart of arms transfers and organisation. It was a base in Syria where the opposition had full control."
He predicted further military operations against remaining rebel strongholds, but on a less intensive scale.
Western and Arab governments, which have already called on Assad to step down and end the bloodshed, expressed mounting concern for civilians struggling to survive in Homs.
Kofi Annan, the U.N.-Arab League envoy on Syria, has said he plans to visit Damascus soon to press for a halt to the violence and better access for humanitarian groups.
Syria took a guarded approach, saying it had asked the United Nations to clarify the nature of Annan's mission.
The Foreign Ministry also said it was ready to discuss a date for U.N. humanitarian chief Amos to visit instead of the "inconvenient" one she had sought
Russia, which along with China, has shielded Syria from U.N. Security Council action, is emerging as a pivotal player in diplomacy over the Syrian crisis.
Moscow has invited Annan for talks on Syria and, according to Kuwaiti officials, will send Foreign Minister Sergei Lavrov to meet his Gulf Arab counterparts in Riyadh next week.
Saudi Arabia and Qatar have led calls for the world to arm Syrian rebels following last month's Russian-Chinese veto of a draft Security Council resolution critical of Syria.
Syria's Foreign Ministry spokesman Jihad al-Maqdisi told al-Manar television that the Saudis and Qataris were "singing from the same hymn sheet" as al Qaeda leader Ayman al-Zawahri, who has urged Arabs and Muslims to support anti-Assad insurgents.
Kuwait's parliament, dominated by Sunni Islamists, said it had agreed to support the Free Syrian Army and urged the Kuwaiti government to cut relations with Syria.
While the Sunni-ruled Gulf monarchies have been alarmed by demands for democracy inspired by revolts across the Arab world, they have also long been at odds with Shi'ite Iran, their non-Arab rival across the Gulf, and with Tehran's Arab allies, Alawite-ruled Syria and the Lebanese Shi'ite group Hezbollah.
Assad's minority, Shi'ite-rooted Alawite sect dominates the political and military elite in Sunni-majority Syria.
The United Nations says Syrian security forces have killed more than 7,500 civilians since the revolt began last March. Syria's government said in December that "armed terrorists" had killed more than 2,000 soldiers and police during the unrest. (Additional reporting by Khaled Yacoub Oweis in Amman, Mariam Karouny, Dominic Evans, Oliver Holmes and Laila Bassam in Beirut, Stephanie Nebehay in Geneva, Steve Gutterman in Moscow and Nour Merza in Dubai; Writing by Alistair Lyon; Editing by Alastair Macdonald)