At least 29 people were killed in the northern city of Aleppo at the weekend by shelling and firefights between Syrian troops and rebels.

President Bashar al-Assad’s forces killed 16 rebels and 13 civilians were killed when planes dropped barrel bombs on the city’s three rebel-held districts late on Saturday.

And both sides blamed the other for an alleged poison gas attack on the rebel-held village of Kfar Zeita north of Damascus.

Rebels said the gas attack happened during air raids that left people suffocating.

But Syria blamed members of the rebel Nusra Front for the attack, saying it had used chlorine gas to kill two people and injure more than 100.