THE battle for control of the besieged Syrian city of Aleppo may have entered a critical phase, as opposition forces make what appears to be a last-ditch attempt to force back the encircling Syrian army, which is backed by Russian air power.

The increased intensity of fighting on the ground and bombardments from the air have led to still more civilian suffering. The United Nations Children’s Fund (UNICEF) said on Monday that the new rebel offensive had forced about 25,000 people, including more than 12,000 children, to be displaced from their homes or shelters in the west of the city, which is under government control. A spokesman for UNICEF, Kieran Dwyer, who is in Syria, said that the civilians “fled instantly last night from this area, with whatever they could leave the door with”. He added that, in the affected neighbourhood, people displaced many times had put up temporary shelters in uncompleted high-rise buildings. At least 30 people were reported to have been killed by rebel shelling of western Aleppo.

When the fighting erupted on Sunday, many people fled to parks, mosques, and wherever “they can feel a bit safe,” Mr Dwyer said. Asked whether more people would be displaced, he replied: “We don’t know what the dynamic of the fighting is going to result in. We are watching and responding at every turn.”

It is reported by UNICEF that in rebel-held eastern Aleppo, which has been besieged for nearly a month, about 300,000 civilians, including more than 120,000 children, are trapped amid the violence, and are in desperate need of food, clean water, and health services. The Russian and Syrian governments say they have set up humanitarian corridors to enable civilians to flee the city. While media footage has shown small numbers of civilians apparently leaving, there has been no mass exodus. Given the heavy fighting, it is hard to imagine how such corridors could be secure. Mr Dwyer insisted that any arrangement to allow food into eastern Aleppo and the safe passage of civilians out of the neighbourhood would need to be co-ordinated through the UN.

On Monday, a Russian military helicopter was shot down by rebels, killing all five people on board. The incident will have done nothing to encourage Moscow to listen to appeals from the UN and other world bodies for a pause in the fighting to allow aid to reach civilians.

On Tuesday, under the cover of further intense Russian bombardment, Syrian troops regained some of the territory lost to the rebels the previous day. In the mean time, children in eastern Aleppo set tyres on fire in the hope that the dense black smoke would make it more difficult for Russian pilots to identify targets in the city.

Diplomatic efforts to end the Syria fighting continue to be led by the US and Russia, with the hope that all sides in the conflict will return to Geneva towards the end of August for a resumption of UN peace talks.

The failure of the region’s governments to respond decisively to the crisis in their midst was plain to see at the recent Arab League summit held in the Mauritanian capital, Nouakchott. The meeting stressed the need to defeat terrorism, and back “all initiatives that can help to end the crises of the Arab world”, including Syria. But it offered no practical suggestions about how this might be achieved.

More to the point, only seven of the 22 Arab League heads of state bothered to attend the summit. Along with the President of Mauritania, they included the leaders of two countries embroiled in internal conflict (Libya and Yemen), and one head of state (of Sudan) accused of genocide by the International Criminal Court.

Christian Aid, CARE International, and World Vision are among 35 aid agencies and humanitarian organisations to have openly condemned a Russia-Syrian proposal to establish “humanitarian corridors” out of eastern Aleppo.

“We consider the proposal deeply flawed on humanitarian grounds and consider it warning for the International Syria Support Group (ISSG) to urgently step up efforts to end the use of brutal siege tactics and illegal attacks on civilians,” the organisations wrote in a statement on Wednesday.

“A true humanitarian operation would not force the people of Aleppo to choose between fleeing into the arms of their attackers or remaining in a besieged area under continued bombardment.”