A Syrian rebel alliance on Sunday announced the start of a battle to recapture the whole of Aleppo, the day after they broke a government siege on rebel-held areas in the country's second city.

The "Army of Conquest", a coalition of rebels and jihadists including the former Al-Nusra Front, said in a statement it would "double the number of fighters for this next battle".

"We announce the start of a new phase to liberate all of Aleppo" after a week of continuous fighting, the group said.

"We will not rest until we raise the flag of the conquest over Aleppo's citadel," it added.

(AFP)