While fighting rages in Syria's largest city of Aleppo, the pro-regime media is telling residents "You ain't seen nothing yet."

Australian Broadcast Company:

Fighting raged in parts of Syria's most populous city through the night and into Thursday, but one security source says the main offensive is still to come.

"The special forces were deployed on Wednesday and Thursday on the edges of the city, and more troops have arrived to take part in a generalised counter-offensive on Friday or Saturday," he said.

Rebel fighters have brought in their own reinforcements, with the source estimating that between 1,500 and 2,000 opposition fighters had arrived from outside Syria's largest city to reinforce some 2,000 already fighting in Aleppo.

"They are mainly present in the southern and eastern suburbs of the city, mainly Salaheddin and nearby districts," he said.

The airport is currently cut off from the city, as four of the five roads leading to it are under rebel control, he added.

Rebels also say a regime assault appears imminent.

"The army's reinforcements have arrived in Aleppo," Colonel Abdel Jabbar al-Okaidi, a spokesman for the rebel Free Syrian Army (FSA) in Aleppo, said.

"We expect a major offensive at any time, specifically on areas across the southern belt, from east to west."

Colonel Okaidi added that some 100 army tanks - as well as a large number of military vehicles - have arrived in Aleppo.

So President Assad will probably succeed in crushing the rebels in both Damascus and Aleppo. But the rebels will simply move on to occupy another city, and the game will go on and on.

We haven't seen the last of the rebels in Aleppo. They'll be back.