The last notable combat actions of the war took place on 3 August 1988, in the Persian Gulf when the Iranian navy fired on a freighter and Iraq launched chemical attacks on Iranian civilians, killing an unknown number of them and wounding 2,300. Iraq came under international pressure to curtail further offensives. Resolution 598 became effective on 8 August 1988, ending all combat operations between the two countries. By 20 August 1988, peace with Iran was restored. UN peacekeepers belonging to the UNIIMOG mission took the field, remaining on the Iran–Iraq border until 1991. The majority of Western analysts believe that the war had no winners while some believed that Iraq emerged as the victor of the war, based on Iraq's overwhelming successes between April and July 1988. While the war was now over, Iraq spent the rest of August and early September clearing the Kurdish resistance. Using 60,000 troops along with helicopter gunships, chemical weapons (poison gas), and mass executions, Iraq hit 15 villages, killing rebels and civilians, and forced tens of thousands of Kurds to relocate to settlements. Many Kurdish civilians fled to Iran. By 3 September 1988, the anti-Kurd campaign ended, and all resistance had been crushed. 400 Iraqi soldiers and 50,000–100,000 Kurdish civilians and soldiers had been killed.