Four Americans taken as prisoners in Yemen

Houthi rebels have taken at least four Americans in Yemen as prisoners, the Washington Post reported Saturday. According to the report, three of the detained were working in the private sector. The fourth is a dual citizen of Yemen and the US. An unnamed US official in the report said that a number of rescues operation were attempted and failed. The hostages are said to be kept in a prison in Sanaa.The detained reportedly have not been harmed physically, though one of them has begun to behave erratically after the recent failed attempt to secure his release.The hostages are said to be among a number of Americans who could not or chose not to leave the country after US embassy was closed in February.Iran-backed Shi'ite Muslim Houthi fighters captured the capital Sanaa in September 2014 and seized the presidential palace in January, driving President Abd-Rabbu Mansour Hadi and his government to resign.After years of crisis, Yemen now risks descending into a full-blown civil war pitting regional, political, tribal and sectarian rivals against each other in a nation that shares a long border with top global oil exporter Saudi Arabia.Yemen is home to al-Qaida in the Arabian Peninsula, one of the most active branches of the global Sunni Islamist group.The United States has long used drones to attack the militants, a strategy critics say has failed to make a decisive difference and has stoked anti-US sentiment.Reuters contributed to this report.