GENEVA (AP) — U.N. human rights experts said Tuesday the governments of Yemen, the United Arab Emirates and Saudi Arabia may have been responsible for war crimes since Yemen's conflict intensified 3½ years ago, including rape, torture, arbitrary detention and use of child soldiers.

Their report — the first since being mandated to investigate by the U.N.-backed Human Rights Council nearly a year ago — is increasing international pressure on the Saudis' Western-backed coalition that already has been widely condemned for devastating airstrikes on civilians as well as combatants.

The U.N. panel al...