The amateur footage shows three small children sitting in the back of an ambulance, all covered in dust.

One little boy sits dazed and silent in the back of the vehicle, trying to wipe the blood from his badly-injured face.

Where was the footage shot?

Activists say it was filmed in the rebel-held al-Qaterji neighbourhood of the divided Syrian city.

The Syrian Observatory for Human Rights, a UK-based war monitor, says the area had been targeted by warplanes, killing three people and injuring several others.

Why is there fighting in Aleppo?

The city is split between the government-held western and rebel-held eastern neighbourhoods.

Fighting for control of the city has intensified in recent weeks, leading to hundreds of deaths and depriving many civilians of power, water and vital supplies.

The city is one of the strongholds of the rebellion to oust Syrian President Bashar al-Assad.

His army is backed on the ground by Shi’ite Muslim militias from neighbouring countries and from the skies by Russian air strikes.

What is the UN saying?

The UN’s special envoy for Syria, Staffan de Mistura, says no aid convoys have reached besieged areas of Syria during the month of August.

De Mistura says he has suspended a humanitarian task force meeting until next week as a signal to major powers.

A 48-hour pause in fighting in the northern Syrian city of Aleppo will be the main topic for Thursday’s meeting of a group of countries working for a cessation of hostilities.

“I insist, on behalf of the UN Secretary General, to have a 48-hour pause in Aleppo. This would require some heavy lifting not only by Russia and the US, the two co-chairs, but also those who have influence on the ground,” De Mistura told reporters.

The UN said last week that two million people lack access to clean water in Aleppo, creating a risk of disease.

Engineers need access to repair electricity networks that drive water pumping stations. (Euronews)