UN envoy condemns rebel bombing of West Aleppo civilians

The UN Special Envoy for Syria has said he is "appalled and shocked" by the rebel attacks on western Aleppo, warning the bombardment could amount to war crimes.

Staffan de Mistura condemned the "high number" of rockets fired by armed opposition groups since beginning a new offensive to break the siege of the divided city.

"Those who argue that this is meant to relieve the siege of eastern Aleppo should be reminded that nothing justifies the use of disproportionate and indiscriminate weapons, including heavy ones, on civilian areas and it could amount to war crimes," De Mistura said in a statement.

The UK-based Syrian Observatory for Human Rights has recorded 41 civilian deaths, including 16 children, since rebel fighters launched a "relentless and indiscriminate" attack on western Aleppo on Friday.

De Mistura reiterated UN Secretary-General Ban Ki-moon's condemnation of the bombing of schools and the use of heavy air power on civilian areas in Aleppo.

"The civilians of both sides of Aleppo have suffered enough due to futile but lethal attempts of subduing the city of Aleppo," De Mistura said, adding: "They now need and deserve a stable ceasefire covering this ancient city of Syria."

Syrian state media has accused rebels of firing shells containing toxic gas into government-controlled districts.

State news agency SANA reported that 35 people were suffering from shortness of breath, numbness, and muscle spasms after "toxic gases" hit the frontline district of Dahiyet al-Assad and regime-held Hamdaniyeh.

Rebels have denied the claims, insisting the regime was responsible for the chemical attacks.

Around 5,000 fighters from the Free Syrian Army and the Salafi-inclined Jaish al-Fatah are involved in the coordinated assaults in a bid to break the regime siege on East Aleppo and gain control of the entire city.