Though the Iranians advanced to within sight of Dukan and captured around and 4,000 Iraqi troops, the offensive failed due to the Iraqi use of chemical warfare. The Iraqis launched the deadliest chemical weapons attacks of the war. The Republican Guard launched 700 chemical shells, while the other artillery divisions launched 200–300 chemical shells each, unleashing a chemical cloud over the Iranians, killing or wounding 60% of them, the blow was felt particularly by the Iranian 84th infantry division and 55th paratrooper division. The Iraqi special forces then stopped the remains of the Iranian force. In retaliation for Kurdish collaboration with the Iranians, Iraq launched a massive poison gas attack against Kurdish civilians in Halabja, recently taken by the Iranians, killing thousands of civilians. Iran airlifted foreign journalists to the ruined city, and the images of the dead were shown throughout the world, but Western mistrust of Iran and collaboration with Iraq led them to also blame Iran for the attack.