The Associated Press reports: The Syrian government launched an offensive Saturday to retake rebel-held neighborhoods in the nation’s commercial hub of Aleppo, unleashing artillery, tanks and helicopter gunships against poorly armed opposition fighters.

Yet after a day of fighting, the rag-tag rebel forces remained in control of their neighborhoods in Syria’s largest city, said activists, suggesting they had successfully fought off the government’s initial assault.

The international community has raised an outcry about a possible massacre in this city of 3 million but acknowledged there was little they could do to stop the bloodshed. The foreign minister of Russia, a powerful ally of Syria, said it was “simply unrealistic” for the Syrian regime to cede control.

The state-controlled al-Watan newspaper celebrated the assault with a banner headline proclaiming the fight for Aleppo “the mother of all battles.”

The rebels are estimated to control between a third and a half of the neighborhoods in this sprawling city, especially a cluster in the northeast around Sakhour neighborhood and in the southwest.

They began their attempt to wrest this key city from the government’s control a week ago. About 162 people have been killed, mostly civilians, according to the Britain-based Syrian Observatory for Human Rights, which does not include soldiers in its toll. Some 19,000 people have been killed since the uprising began in March 2011, estimated the group.

For Saturday, activists estimate that at least two dozen have died so far in the day’s fighting.

Local activist Mohammed Saeed said the rebels have managed to keep the regime’s tanks at bay so far with rocket-propelled grenades.

“The army hasn’t been able to take any neighborhoods yet, there are too many from the Free Syrian Army,” Saeed said, referring to the rebels.

He estimated that about 1,000 fighters had poured into the city in the past few days to take on the Syrian army, which had been massing forces around the city ahead of its attack.

By the end of Saturday, according to the Observatory, the government appeared to have pulled back from its ground offensive and was resuming its bombardment of various neighborhoods with artillery. Attack helicopters pounded rebel positions.