Two US citizens held by Houthi rebels in Yemen have been released and flown to neighbouring Oman. <br/><br/>US Secretary of State John Kerry said The Americans, who were not identified, left the country together with Yemenis hurt in a recent funeral bombing. <br/>The US thanked Oman for mediating and acknowledged the humanitarian gesture from the rebels. <br/><br/>Yemen has been devastated by a war between government forces and those allied to the Houthi rebel movement. <br/><br/>More than 6,800 people have been killed since March 2015, the majority in air strikes by a Saudi-led multinational coalition that backs the President against the Houthi rebels.<br/><br/>Speaking in Switzerland after multilateral talks on Syria, Mr Kerry welcomed the development.