The United Nations on Wednesday marked the first World Humanitarian Day to pay tribute to humanitarian workers killed in missions, including the 22 UN staffers who died in a Baghdad attack six years ago, according to dpa. Among those killed in Baghdad on August 19, 2003 was Sergio Vieira de Mello, the Brazilian chief of the UN mission in Iraq, which was freshly set up following the US invasion of Iraq to oust Iraqi dictator Saddam Hussein. The UN mission in Iraq, located then at the Canal Hotel in Baghdad, was blown up by a massive bomb while it was fully staffed. In another recent attack,the UN office in Algiers was bombed in December 2007, killing 17 local and foreign staffers. UN Secretary General Ban Ki-moon told a crowd of foreign diplomats and UN staffers at UN headquarters in New York that the day was meant to renew the UN's commitment to help "vulnerable, voiceless and marginalized people wherever they may be." "This is also a day on which we pay tribute to the legions of heroic humanitarian personnel," Ban said. "These men and women come from many backgrounds. But they share a conviction that one person's suffering is everyone's responsibility." The UN decided to hold the annual World Humanitarian Day on August 19 to "shine a spotlight" on people in need of assistance worldwide.