 Complete the following phrase:  When the returned delegation informed John II Casimir of Khmelnytskys new campaign the king called for all szlachta volunteer army, while sending the regular troops against cossacks to southern Volhynia. However, after obtaining an intelligence report of the superior cossack forces, the Polish troops retreated to Zbarazh to set a defense. The forces of Jeremi Wiśniowiecki reinforced the Zbarazh defenders while he took the lead of all Polish forces. Khmelnytsky besieged the city wearing down through series of random attacks and firing at it. The king while rushing to help Wiśniowiecki was ambushed with his newly gathered forces. Khmelnytsky leaving part of his army with Ivan Cherniata near Zbarazh moved together with İslâm III Giray to intercept the Polish reinforcements and block their way at a river crossing near 