As fighting continues in the Syrian city of Aleppo, a steady flow of dead and injured opposition fighters is being brought back to their base.
At least 30 people are reported to have been killed, with some reports saying the dead include civilians.
Government forces continue to bombard parts of Aleppo, but ground forces appear to have made little progress in areas held by rebels.
The BBC reports that the struggle for control of Aleppo has settled back into a pattern of heavy, but sporadic bombardment of parts of the city held by the rebel Free Syrian Army (FSA).
Rebels with the FSA say they have repelled an army incursion and destroyed tanks, but there is no independent verification.
The international envoy to Syria, Kofi Annan, says the latest events in Aleppo show the need for international efforts to bring about a political transition.
"The escalation of the military build-up in Aleppo and the surrounding area is further evidence of the need for the international community to come together to persuade the parties that only a political transition, leading to a political settlement, will resolve this crisis," said Mr Annan in a statement.
But a Syrian opposition leader has urged foreign allies to circumvent the divided U.N. Security Council and intervene.
"Our friends and allies will bear responsibility for what is happening in Aleppo if they do not move soon," said Abdelbasset Sida, the head of the Syrian National Council which is the main umbrella group for opposition to President Bashar al-Assad.
"Any action has to be from outside the Security Council through an Arab League initiative and through a resolution passed by the General Assembly," he said on Sunday on a visit to the United Arab Emirates for talks with officials.
Hundreds of people have fled by road during the latest fighting to escape the violence and deteriorating conditions.