If the security situation in Iraq continues to improve, the number of refugees and displaced people returning to their homes could more than double this year to 500,000, the UN refugee agency said Thursday. After years of extreme violence Iraq is now experiencing markedly improved security, said Daniel Endres, Baghdad representative of the Geneva-based agency. "Although this security remains fragile, last year we saw a significant return as a result," he told journalists in Brussels. More than 220,000 Iraqis who fled abroad or were displaced within the country after the US-led invasion returned home in 2008, according to UN statistics. Still, nearly two million remain outside the country, mostly in Syria and Jordan, and an additional 1.6 million, forced from their homes by sectarian and ethnic violence, are displaced inside Iraq.