CAIRO — The United Nations World Food Programme said Tuesday that an aid worker has died in a Yemeni prison three weeks after his detention by Houthi rebels. The announcement came a day after the U.N. suspended its operations in the rebel’s stronghold in northern Yemen .

The United Nations has paused all operations in Yemen's Sa'ada governorate after more U.N. staff were detained by the Houthi authorities, deputy U.N. spokesperson Farhan Haq said on Monday. "This extraordinary and temporary measure seeks to balance the imperative to stay and deliver with the need to have the safety and security of the U.