Oil is dropping on Thursday following several days of increases despite continued hostilities between the U.S. and Iran. Tehran has vowed to "punish" the U.S. after the country conducted what it described as a "heavy wave of strikes" against Iran. "The strikes aimed to further diminish threats posed by Iran and its proxies to American forces, commercial shipping, and neighboring Gulf countries," it added. The Iranian revolutionary guard said three members were killed in attacks in the northwestern province of Zanjan. Egypt said on Thursday that a drone hit two ships at its Mediterranean port of Damietta the day before.