Syrian troops responded by driving the jihadists from the Sukkari district with the aid of Russian aid strikes and penning them into Salaheddine and Sayf al-Dawla, a combined area of less than one square mile.

Rebel shelling in return killed six civilians in government-held areas of the city and injured dozens more.

The deal struck between Russia and Turkey on Tuesday unravelled while the remaining militants and their families were set to be taken to a town north-east of the city at 5am.