By Phil Stewart and Idrees Ali WASHINGTON (Reuters) - The Pentagon declined to say on Monday whether the USS Mason destroyer was targeted by multiple inbound missiles fired from Yemen on Saturday, as initially thought, saying a review was under way to determine what happened. Any determination that the USS Mason guided-missile destroyer was targeted on Saturday could have military repercussions, since the United States has threatened to retaliate again should its ships come under fire from territory in Yemen controlled by Iran-aligned Houthi fighters. The United States carried out cruise missile strikes against radar sites in Yemen on Thursday after two confirmed attempts last week to hit the USS Mason with coastal cruise missiles.