Secretary-General Antonio Guterres is urging people everywhere to protect the millions of civilians trapped in conflicts around the worldinfo-icon who are routinely being killed in direct and indiscriminate attacks.

He told a U.N. event on the eve of World Humanitarian Day on Saturday that protecting civilians, humanitarian workers and healthinfo-icon care staff is required under international law, "yet in warinfo-icon zones all over the world, parties to conflictinfo-icon are flouting their obligations."

Guterres said: "We are here to tell the world: Civilians in conflict are not a target."

U.N. humanitarian chief Stephen O'Brien said that since the General Assembly designated World Humanitarian Day in 2008 "many thousands of aid workers have been killed in direct or indirect attacks."

Last year, he said, 288 aid workers were targeted in 158 attacks.