Iran and the United States traded new attacks and threats Sunday, the fourth straight day of hostilities, with little sign of a de-escalation that would get their 2-week-old ceasefire back on track. Iran's Revolutionary Guard said in a statement carried by Iranian state media that it had targeted a U.S. naval base in Bahrain and the Ali Al Salem Air Base in Kuwait in retaliation for American attacks. The governments of Kuwait and Bahrain said the attacks had not caused any casualties.