UN chief urges Yemen's Houthis to release aid workers

United Nations Secretary-General Antonio Guterres on Tuesday demanded Yemen's Houthi rebels release dozens of aid workers, including UN staff, a year after their arrest.

The Iran-backed rebels, who control much of the war-torn country, detained 13 U.N. personnel and more than 50 employees of aid groups last June.

"I renew my call for their immediate and unconditional release," Guterres said in a statement issued by the office of his special envoy for Yemen, Hans Grundberg.

"The U.N. and its humanitarian partners should never be targeted, arrested or detained while carrying out their mandates for the benefit of the people they serve," he added.

A decade of civil war has plunged Yemen into one of the world's worst humanitarian crises, with more than half of the population relying on aid.

The arrests prompted the United Nations to limit its deployments and suspend activities in some regions of the Arabian Peninsula's poorest country.

The Houthis at the time claimed an "American-Israeli spy cell" was operating under the cover of aid groups -- an accusation firmly rejected by the U.N.

Guterres also lamented the "deplorable tragedy" of the death in detention of a World Food Program staffer in February.

The Houthis have kidnapped, arbitrarily detained and tortured hundreds of civilians, including aid workers, during their war against a Saudi-led coalition supporting the beleaguered internationally recognized government.