Some foreigners are fighting in Syria’s largest city, Aleppo, alongside rebels who say they are disappointed that more residents have not joined their cause.Reporting from the frontline, Al Jazeera’s Zeina Khodr says the young rebels in the city have come mainly from the countryside of Aleppo province.It has not been easy to stand up against the Syrian army, especially when the city did not rise up when rebels entered some poor neighbourhoods and set up bases, she says."We saw a few Arab fighters from Saudi Arabia and Egypt who didn’t want to be filmed,” our correspondent said, adding that some of the foreign fighters claimed allegiance to al-Qaeda."Undoubtedly the majority of the fighters here are Syrians, but this war has attracted Arabs who feel obliged to help the opposition, who are mainly Sunni Muslims.”Al Jazeera’s Khodr also says the authorities still enjoy some backing in Aleppo, either out of fear of the state or fear of an opposition that has no clear agenda apart from toppling President Bashar al-Assad.Allepo, which is Syria’s financial capital, had long been immune from the fighting in the countryside. However, now the conflict has divided the people along class and religious lines, she says.Damascus shellingThe developments in Aleppo come amid renewed assault by the Syrian army on the southern neighbourhoods of Damascus, residents and activists said on Wednesday.At least 40 people were killed in the shelling, which was accompanied by attacks from helicopters, and in ensuing ground raids on the Kfar Souseh, Daraya, Qadam and Nahr Aisha neighbourhoods, they said.