Saudi Arabia released seven prisoners it was holding from Yemen's Houthi movement, who were flown to the Houthi-controlled capital Sanaa on Wednesday by the Red Cross, the day after a Saudi prisoner freed by the Houthis arrived in Riyadh.
The apparent swap comes as Yemen's warring parties are still hammering out details of a larger prisoner exchange that they agreed last month as a confidence-building gesture at the first major peace talks of the nearly four-year-old war.
The U.N. special envoy to Yemen, Martin Griffiths, welcomed the release and said he hoped it would encourage the rapid implementation of the larger prisoner swap.