U.S., U.K. launch fourth round of joint airstrikes on Houthi targets

Read MoreThe U.S. and U.K., with the support of its allies, launched a fourth round of retaliatory airstrikes Saturday on Iranian-backed Houthi targets in Yemen.The U.S. and U.K., with the support of its allies, launched a fourth round of retaliatory airstrikes Saturday on Iranian-backed Houthi targets in Yemen.