First Crimean Tatar units appeared near Kamieniec Podolski on August 12, and two days later, main Ottoman army camped by the town. After building seven large sconces, Turkish artillery began a barrage with its 120 modern cannons. It paralyzed Polish defence, and on August 20, the Turks managed to score a direct hit in one of the towers of the Old Castle, which served as an ammunition depot.