BEIRUT—Syria’s antigovernment rebels claimed a stunning advance into Aleppo, a major symbolic and strategic prize, in a setback for the government in Damascus and its allies Russia and Iran.Islamist-led insurgents poured into Aleppo two days after launching an unexpected strike from the country’s rebel-held northwest and eight years after the city fell to forces loyal to the government of Bashar al-Assad at the end of a long siege.

Syria state media say government troops are battling insurgents inside the country’s largest city Aleppo for the first time since 2016

Syrian authorities closed Aleppo airport and cancelled all flights on Saturday, three military sources told Reuters, as rebels opposed to President Bashar al-Assad said they had reached the heart of the city.