Russia says it has carried out air strikes against Syrian rebels it accuses of wounding more than a hundred people in the city of Aleppo with a chemical attack.<br />The Syrian government also blamed the rebels, showing images on state media of Aleppo residents being treated in hospital as they struggled to breathe. <br />The rebels denied the allegations, saying Moscow and Damascus are using the claims as a pretext for an attack on opposition-held areas.<br />There had been no major offensive in northern Syria since September, when Russia and Turkey, which backs the rebels, agreed to create a buffer zone to separate government forces from rebel fighters in Idlib province. <br />
