Afghanistan, Aug. 19 -- The United Nations on Wednesday marked World Humanitarian Day by remembering the 22 people killed in the 2003 bombing of its headquarters in Baghdad, an attack that became a defining moment for the safety of humanitarian workers worldwide.

The attack on the Canal Hotel in Baghdad on August 19, 2003, killed 22 people, including Sergio Vieira de Mello, the UN secretary-general's special representative for Iraq, and injured more than 150 others. The bombing was carried out by a suicide attacker in a truck loaded with explosives.

The United Nations said it continues to honour humanitarian workers who risk their lives to assist people affected by conflict and disasters. World Humanitarian Day is observed each year on Au...