The divided Syrian city of Aleppo has seen intensified fighting between the Syrian army and rebel forces. Syrian government forces, backed by Russian fighter jets, have been pounding rebel-held positions in Aleppo in an attempt to crush a major insurgent campaign to break the siege of the city. Residents of the rebel-held parts of Aleppo have resorted to burning tyres, sending up big plumes of black smoke in the hope of preventing air strikes.

Siege of Aleppo
Opposition fighters drive a tank in the Al-Huweiz area on southern outskirts of AleppoOmar haj Kadour/AFP
Siege of Aleppo
Free Syrian Army fighters shoot a weapon on the back of a pick-up truck in RamousahAbdalrhman Ismail/Reuters
Siege of Aleppo
A warplane makes an air strike on the rebel held al-Rashideen neighbourhoodAmmar Abdullah/Reuters
Siege of Aleppo
Damaged trucks are pictured after an airstrike on a parking area in the rebel-held town of Atareb in Aleppo provinceAmmar Abdullah/Reuters
Siege of Aleppo
A man rides a bicycle past burning tyres used to create smoke cover from warplanesAbdalrhman Ismail/Reuters
Siege of Aleppo
A man burns bedding on a road in Aleppo to create smoke cover from warplanesAbdalrhman Ismail/Reuters
Siege of Aleppo
Smoke from burning tyres rises over damaged buildings in AleppoAbdalrhman Ismail/Reuters

Syrian rebel fighters had launched a major assault on government-held south western parts of Aleppo to try to reopen supply lines into opposition-held areas of the city after the army and its allies tightened their siege. Government troops encircled rebel-held areas of the city on 17 July. Rebel groups are battling to break through a strip of government-controlled territory and reconnect their encircled sector of eastern Aleppo with a swathe of insurgent territory in the west of Syria. This would open a new route south of the city for a quarter of a million civilians in eastern Aleppo who are under siege.

Siege of Aleppo
The road that civilians would have to use to access one of the safe points opened for civilians to leave rebel-held areas, is pictured in Aleppo's Bustan al-Qasr. The Municipal Palace, which is controlled by forces loyal to Syria's President Bashar al-Assad, is pictured in the backgroundAbdalrhman Ismail/Reuters
Siege of Aleppo
The Municipal Palace, which is controlled by forces loyal to Syria's President Bashar al-Assad, is pictured from a rebel-held area of AleppoAbdalrhman Ismail/Reuters
Siege of Aleppo
Aleppo's historic citadel, controlled by forces loyal to Syria's President Bashar al-Assad, is seen from a rebel-held area of the cityAbdalrhman Ismail/Reuters
Siege of Aleppo
Forces loyal to Syria's President Bashar al-Assad walk past rubble after they advanced on the southern side of the Castello road in AleppoSana/Reuters
Siege of Aleppo
A man holds one of the leaflets dropped by the Syrian army over opposition-held Aleppo districts, asking residents to cooperate with the military and calling on fighters to surrenderAbdalrhman Ismail/Reuters
Siege of Aleppo
Boys read one of the leaflets dropped by the Syrian army over rebel-held areas of AleppoAbdalrhman Ismail/Reuters

The Great Battle for Aleppo, as some Syrians have CALLED it, involves a loose coalition of rebel groups united against a common enemy. the newly-formed Islamist group Jabhat Fatah al Sham (formerly the al Qaeda-linked Nusra Front) are pushing from the south of the city while fighters from Free Syrian Army (FSA) brigades are clashing with government forces on a number of fronts.

The heaviest fighting is centred around the strategic Ramousah area south west of Aleppo, where rebel forces have been firing tanks and mounted artillery towards forces loyal to Syrian President Bashar al-Assad.

Siege of Aleppo
Rebel fighters pray and rest in a building in the Ramousah neighbourhood on the southern outskirts of AleppoThaer Mohammed/AFP
Siege of Aleppo
Damaged vehicles are piled on the roof of a mechanic service centre in RamousahAbdalrhman Ismail/Reuters
Siege of Aleppo
Free Syrian Army fighters walk with their weapons in RamousahAbdalrhman Ismail/Reuters
Siege of Aleppo
A Free Syrian Army fighter cleans the wound of a fellow fighter in RamousahAbdalrhman Ismail/Reuters
Siege of Aleppo
Free Syrian Army fighters rest with their weapons in the Ramousah area, southwest of AleppoAbdalrhman Ismail/Reuters

The United Nations Children's Emergency Fund (Unicef) says it is "extremely" concerned for the safety and well-being of children caught up in the violence engulfing Aleppo. Unicef regional director Saad Houry called for unhindered humanitarian access to the divided city and for children to be protected. Unicef says children make up a third of the 300,000 residents trapped in rebel-held besieged neighbourhoods.