Houthi rebels in Yemen have freed at least five foreign hostages kidnapped earlier this year, including two Americans.
All were freed Sunday following negotiations between the rebels and the government of Oman. Details on the talks or why the hostages were kidnapped in the first place are unclear.
None of the hostages has been identified. But the New Orleans-based company Transoceanic Development, which helps deliver humanitarian aid, says one of its employees, Scott Darden, is among them.
White House spokesman Ned Price said the United States is deeply appreciative to all those who worked to free the captives, especially Omani leader Sultan Qaboos bin Said al-Said.
"This outcome underscores that we have been, and will continue to be, tireless in pursuing the release of all Americans detained abroad unjustly, including those who remain in the region," Price said.
Several other Westerners held in Yemen have been freed in recent months, some thanks to Omani mediation.
Yemeni tribesmen frequently have kidnapped Western hostages to try to win concessions from the government. Nearly all were eventually freed unharmed. But U.S. journalist Luke Somers and a teacher from South Africa, Pierre Korkie, were killed during a failed attempt by U.S. forces to rescue them from al-Qaida last year.
Iranian-backed Houthi rebels seized Yemen's capital, Sana'a, last year, forcing the internationally recognized government to flee to Saudi Arabia.
Heavy fighting on the ground and Saudi-backed airstrikes on the rebels have created a humanitarian catastrophe in Yemen, with 80 percent of its population in desperate need of food and aid.
The United States is demanding that all sides take part in peace talks without preconditions, saying it is clear the Yemeni people want the fighting to end as soon as possible.