"The Saudi-led coalition fighting in Yemen may be responsible for "international crimes", a category that includes war crimes and crimes against humanity, the top U.N. human rights official said on Friday. Zeid Ra'ad Al Hussein, United Nations High Commissioner for Human Rights, condemned an air strike in Yemen this week and added that the coalition was "responsible for twice as many civilian casualties as all other forces put together". More than 6,000 people have been killed since the coalition campaign began a year ago to fight Iranian-allied Houthis and forces loyal to ex-president Ali Abdullah Saleh and to restore the president they ousted, Abd-Rabbu Mansour Hadi. Tuesday's strike near Mustaba in northwest Yemen hit an outdoor market and killed more than 100, a provincial health director and a U.N. official in Sanaa said, making it one of the deadliest attacks in the war."