A U.S. Navy ship fired three warning shots after an Iranian fast-attack craft approached and circled two U.S. Navy ships and a Kuwaiti vessel in the northern Gulf on Wednesday, CNN reported on Thursday. It said the U.S. ship fired the shots into the water after the Iranian ship did not leave after a brief radio conversation, CNN said, citing U.S. officials. The United States on Wednesday had reported another incident in which it said Iranian vessels harassed a U.S. warship near the Strait of Hormuz on Tuesday.