Aleppo: BBC journalist on Syria warplanes bombing city
It has been another day of intensive fighting.
Clashes erupted in many neighbourhoods as the rebels tried to consolidate their hold on territory they had seized so far and advance in other areas.
The thud of heavy gunfire echoed around parts of the city that has become a critical battleground between the armed opposition and forces loyal to President Assad.
Snipers from both sides exchanged high-calibre shots as the volleys from street battles increased.
But the military's response marked a sharp escalation in this battle.
Helicopter gunships spun through the skies throughout the day, firing bullets and rockets to the ground. Sustained artillery and mortar rounds pounded restive neighbourhoods.
But it was what happened late in the afternoon that underlined the grave risk to the government of losing ground in what is Syria's largest city and its economic capital.
First came an unmistakeable sound that has so far been absent in this conflict - the roar of fighter jets.
What appeared to be Russian-made MiG planes arced through the sky. We watched as they dropped in, bombing and strafing rebel positions.
Dead and wounded civilians and fighters were taken to hospitals and makeshift clinics as the human cost of this conflict continues to grow.
The stakes for both sides here could not be higher and it is now clear that neither side is prepared to give way.