At least 15 people were killed and 55 others were wounded Friday by mortar shelling on government-controlled areas in the northern city of Aleppo, media reports said.The shelling targeted several residential areas in the government-controlled parts in western Aleppo, the latest in a series of attacks the rebels in eastern Aleppo are waging to quell the momentum of the Syrian government forces, which are making notable gains in Aleppo, Xinhua quoted state news agency SANA as saying.Meanwhile, a military source said that the Syrian army has captured several buildings in the rebel-held areas of Slaiman al-Halabi. The army also seized parts in the Bustan al-Basha area in the old city of Aleppo, including a church.This comes as the Syrian army succeeded to recapture the Handarat Camp for Palestinian refugees, after taking and losing it again last week.The renewed military showdown in Aleppo came just two weeks after a Russia-US brokered truce expired with no extension.