Syrian opposition forces have taken control of much of the country’s second largest city Aleppo, according to residents in the city and video verified by CNN. A rebel alliance launched a surprise attack this week,

By Saturday, they had taken control of "large parts" of the country's second-biggest city, Aleppo. The surprise offensive prompted the first Russian strikes on Aleppo since 2016, and saw Syria's military withdraw its troops from the city.

Russian and Syrian warplanes targeted insurgents in an Aleppo city suburb on Saturday, two Syrian military sources said, after the rebel fighters penetrated the heart of the city in Syria's northwest in a surprise attack the previous day.