At least 22,300 Iraqis who fled to Syria have returned home in the past three weeks, United Nations officials in Baghdad said Tuesday, preparing for more refugees fleeing the escalating Syrian civil war. The returning Iraqis have been joined by some 3,600 Syrians who have crossed into Iraq since July 23, when Baghdad announced it was opening its western borders to refugees. The U.N. envoy to Iraq, Martin Kobler, welcomed the Iraqi government's efforts to aid the new arrivals, but he said international donors must contribute more money. More than 1 million Iraqis fled to Syria to escape widespread sectarian fighting during the worst of violence in their homeland between 2005 and 2007. They began to return to Iraq in large numbers after July 17, when Iraq's government urged its citizens to return home immediately to avoid being hurt or killed in the Syria fighting.