The Russian military says Syrian rebels have used a toxic agent against civilians in eastern Aleppo. Lieutenant General Sergei Chvarkov, head of the Russian reconciliation centre in Syria, says the attack on Tuesday killed seven and sickened another 23 people in a residential area. 

Chvarkov didn't identify the substance used, but said the victims suffocated or suffered lung burns. He also said the attack was launched by the militant group Nour el-Deine Zengi and that the US has been informed. Also on Tuesday, Syrian rebels accused the government of using toxic gas against civilians in the north of the country. None of the claims can be independently verified.