The Saudi state news agency SPA reported Wednesday that the prisoner swap was mediated by Yemeni tribal leaders but provided few additional details.

The move may be a confidence-building measure as warring parties in Yemen are trying to restart talks to end the war.

The tribal delegation reportedly helped negotiate a lull in fighting to allow humanitarian deliveries to parts of Yemen near the border.

SPA quoted a Saudi statement as saying "the leadership of the coalition forces welcomed the continuation of a state of calm along the border ... which contributes to arriving at a political solution."

The prisoner exchange came a day after Yemeni officials said a Houthi delegation had visited Saudi Arabia.

Saudi Brig. Gen. Ahmed al-Asiri said on television Wednesday that there were no direct talks with the Houthis but that there were talks with tribal figures who are serving as mediators.

The multifront conflict pits Houthi rebels and forces tied to former President Ali Abdullah Saleh against forces loyal to Yemeni President Abed Rabbo Mansour Hadi, southern Yemeni secessionists and tribal units. The conflict has opened room for al Qaeda and the so-called "Islamic State" to make inroads.

Saudi Arabia and Gulf Arab allies have been in a stalemated air and ground campaign since last year to back forces loyal to Hadi after Shiite Houthi rebels took the capital and large swaths of territory.

Saudi Arabia has accused its regional rival Iran of supporting the Houthi rebels. Houthis have denied the accusations.

Nearly 6,000 people have died in more than a year of fighting in Yemen, creating a humanitarian catastrophe that has affected nearly 80 percent of the population. Nearly 7.6 million people suffer from food insecurity.

The conflict has been marked by possible war crimes and abuses committed by all sides.

cw/sms (AP, Reuters)