Newly recruited Houthi fighters chant slogans as they ride a military vehicle during a gathering in the capital Sanaa to mobilize more fighters to battlefronts to fight pro-government forces in several Yemeni cities, on January 3, 2017.

Five staff members of the International Medical Corps and two contracted drivers were safely released Sunday, the aid organisation said, a day after announcing their detention by Yemen’s Houthi militia.

The seven — all “locally hired” — had been at a hotel in the central province of Ibb when they were detained, the US-based non-governmental organisation said in a statement.

International Medical Corps did not say for how long the aid workers had been held or provide details on the circumstances of their release.

The organization’s website says it has more than 150 local staff in Yemen and that it has operated since 2012 in the war-torn country.

It says its relief efforts provide a lifeline for families in the rebel-held capital and in Ibb, as well as the flashpoint southwestern city of Taez, and Aden and Lahj in the south.

The Houthis and their allies control most of Yemen’s north and west, while forces loyal to President Abedrabbo Mansour Hadi, backed by an Arab coalition, control the south and east.