The Syrian rebel force fighting government troops in the besieged city of Homs says most of its fighters have left the Baba Amr district in a "tactical" withdrawal.
The Free Syrian Army (FSA) said it was pulling out of Baba Amr, which has been heavily shelled for nearly a month.
Syrian government forces say they now have full control of the district.
The International Red Cross and Syrian Red Crescent say they have permission to enter Baba Amr on Friday.
They plan to bring bring food and medical supplies, and will also evacuate those in need, ICRC spokeswoman Carla Mardini told the BBC.
"We fear there are many people who are seriously wounded," she said. "We know humanitarian situation on the ground is extremely worrying."
A network of activists, the Local Co-ordination Committees (LCC), said the number of people killed on Thursday had risen to 26. At least 17 people had died in Homs, the LCC said.
The Syrian government has said it is fighting armed gangs and terrorists since the uprising began 11 months ago. In all, at least 7,500 people have died, the UN estimates.
The head of the FSA, Col Riyad al-Asaad, said government troops had already moved in and were combing the area.
A few fighters remained behind in Baba Amr to cover the retreat, the FSA said.
A statement posted online in the name of the Baba Amr brigade of the FSA said the fighters did not have enough weapons to defend the civilians.
The BBC's Jim Muir, in neighbouring Lebanon, says the FSA's withdrawal was probably by agreement between the two sides, as has happened elsewhere in Syria, to avoid a final showdown.
The number of civilians remaining in Baba Amr, which normally has a population of 100,000, cannot be independently confirmed.
The FSA says 4,000 civilians are refusing to leave their homes.
The statement also warns the government forces not to harm civilians, saying the opposition would take severe revenge if they did.
It has been snowing heavily in Homs, slowing the advance of ground troops which began their offensive on Tuesday, but also worsening conditions for civilians.
Many of those still in Baba Amr are without power and running low on basic supplies.
Hundreds of people died during the month-long bombardment, activists say.
The activist Revolutionary Council of Homs said it could no longer reach anyone inside Baba Amr, the Associated Press reported. All satellite signals were jammed, it said.
Two French journalists trapped in Homs, one of them seriously wounded, remain unaccounted for.
Meanwhile, the exile political opposition Syrian National Council (SNC) says it has formed a military bureau to co-ordinate the various armed anti-government groups.
Announcing the creation of the new bureau, SNC leader Burhan Ghalioun said the uprising had begun as a non-violent movement, but the council had to "shoulder its responsibilities in light of this new reality".
Mr Ghalioun said the bureau would function like a defence ministry and would be staffed by soldiers from the FSA as well as civilians.
However, the head of the FSA, Col Riyad al-Asaad, has said his organisation will not co-operate with the new bureau, our correspondent says.
That is extraordinary, our correspondent explains, because the announcement specifically mentioned that the bureau was being established in order to provide arms to the FSA, as well as political control.
What Col Assad is saying is that the FSA does not want any political interference and has its own military strategy, which is to keep fighting the government, our correspondent adds.
In other developments:
- Foreign ministers of the six Gulf Arab states have said they will meet Russian Foreign Minister Sergei Lavrov next week to "express disappointment with the Russian stance", according to the AFP news agency
- UN-Arab League peace envoy Kofi Annan has called for unity behind a single mediation effort
- Britain has confirmed it is withdrawing its remaining diplomatic staff from Damascus because of security concerns
- Syria has responded to criticism that it refused to allow UN rights official Valerie Amos into the country, saying she had requested "an unsuitable time", and promising to continue consultations.
Meanwhile, the UN's rights council has passed a resolution condemning "systematic violations" against civilians and calling for aid agencies to be allowed access.
China and Russia, which both vetoed two UN Security Council resolutions in Syria, voted against the proposal, as did Cuba.
The vote carries no legal weight, but analysts say it may embolden diplomats to take a tougher line in Security Council debates.