In March and early April, nearly two million Iraqis, 1.5 million of them Kurds, escaped from strife-torn cities to the mountains along the northern borders, into the southern marshes, and to Turkey and Iran. By April 6, the United Nations High Commissioner for Refugees (UNCHR) estimated that about 750,000 Iraqi Kurds had fled to Iran and 280,000 to Turkey, with 300,000 more gathered at the Turkish border. The approach towards the refugee immigration was met with a different approach by Iran and Turkey. Iran had opened its borders to the refugees, while Turkey first closed its borders and only opened its borders following international pressure and assurances of financial help to cope with the refugees. Iran also received much less international help to cope with the crisis than Turkey, mainly due to their strained relations with the USA. According to accounts from international relief organizations cited by Nader Entassar, Turkey received more than seven times the amount of help per refugee, as Iran received. Their exodus was sudden and chaotic with thousands of desperate refugees fleeing on foot, on donkeys, or crammed onto open-backed trucks and tractors. Many were gunned down by Republican Guard helicopters, which deliberately strafed columns of fleeing civilians in a number of incidents in both the north and south. Numerous refugees were also killed or maimed by stepping on land mines planted by Iraqi troops near the eastern border during the war with Iran. According to the U.S. Department of State and international relief organizations, between 500 and 1,000 Kurds died each day along Iraq's Turkish border. According to some reports, up to hundreds of refugees died each day along the way to Iran as well.