Yemeni tribal and security officials say a U.S. drone strike Monday killed at least four suspected al-Qaida insurgents, the third American drone attack in a week.
Authorities said the latest attack targeted a car in Baida province that may have been loaded with arms and explosives.
Washington has launched more than 100 attacks, mostly from drones, against militants in the unsettled Arabian Peninsula country since 2009.
Three have been launched since U.S. President Barack Obama declared January 25 that there would be no let-up in the U.S. attacks in Yemen, even after Shi'ite Houthi rebels took control of the capital, Sana'a, and forced the resignation of Western-supported President Abed Rabbo Mansour Hadi.
The Houthis have demanded involvement in the country's army and police force, and their militia on Sunday set a three-day deadline for Yemeni political parties to "fill the vacuum" left by the resignations of Hadi and his prime minister on January 22, Reuters reported. A United Nations envoy said Hadi and his cabinet are effectively under house arrest.
Mass grave reported
In Iraq, Kurdish forces say they have found a mass grave of about 25 members of the Yazidi minority believed killed by Islamic State militants as they swept through northwest Iraq in recent months.
Officials said Kurdish peshmerga forces found the gravesite Sunday, with the bodies of men, women and children.
Islamic State insurgents are believed to have killed hundreds of the Yazidi ethnic minority and buried alive some of their victims. About 300 women have been kidnapped as slaves.
Jordanian pilot's fate unclear
Meanwhile, the fate of the Jordanian fighter pilot being held by the Islamic State remains uncertain.
Jordan's King Abdullah II said Sunday his country is doing everything it can to rescue Muath al-Kaseasbeh, whom he described as a "hero pilot."
Amman renewed its pledge to release an Iraqi insurgent on death row in Jordan, Sajida al-Rishawi, if given proof that the pilot is still alive. The effort came in the aftermath of the jihadists' beheading of Japanese journalist journalist Kenji Goto, whose mutilated body apparently was shown in a video released Saturday.
His wife, Rinko Jogo, said Monday that she is devastated by Goto’s death. But she said she remains "extremely proud of my husband, who reported the plight of people in conflict areas like Iraq, Somalia and Syria."