A Syrian government airstrike hit a crowded vegetable market in an opposition-held neighborhood of the northern city of Aleppo on Saturday, killing at least 21 people, activists said, according to AP. For nearly two weeks, Regime's warplanes and helicopters have pounded opposition-controlled areas of the divided city. Activists say the aerial assault has killed more than 400 people since it began Dec. 15. The campaign comes in the run-up to an international peace conference scheduled to start Jan. 22 in Switzerland to try to find a political solution to Syria's civil war. Some observers say the Aleppo assault fits into Assad's apparent strategy of trying to expose the opposition's weakness to strengthen his own hand ahead of the negotiations. Saturday's airstrike slammed into a marketplace in the Tariq al-Bab neighborhood, the Aleppo Media Center activist group and the Britain-based Syrian Observatory for Human Rights said.