The International Committee of the Red Cross (ICRC) has called on all sides in a widening conflict in Yemen to obey the rules of war, voicing concern at reports of civilian casualties following Saudi-led air strikes.
Warplanes from Saudi Arabia and Arab allies struck Shi'ite Muslim rebels fighting to oust Yemen's president on Thursday, a gamble by the world's top oil exporter to check Iranian influence in its backyard.
In a statement, the ICRC urged all sides to protect civilians and medical facilities, ensure the wounded get medical attention, and treat detainees humanely, in line with the Geneva Conventions.
"All parties involved in the current round of violence are bound by the rules governing the conduct of hostilities," said Cedric Schweizer, who heads an ICRC delegation of 300 aid workers in Yemen.
Under international humanitarian law, all countries and parties involved in the conflict must distinguish between military and civilian objects, and uphold the principles of proportionality and precaution, the ICRC said.
The independent aid agency said it had donated supplies to hospitals in Taiz and Aden, which have received dozens of wounded people in recent days.
It also provided body bags and medical supplies to three hospitals that handled casualties from suicide bombings at mosques in the capital Sanaa last week that killed more than 130 people.