A US vessel fired warning shots at more than a dozen Iranian fast attack boats which buzzed close to a US Navy submarine and escort ships in the narrow Strait of Hormuz Monday, the Pentagon said. In the second such incident in two weeks, 13 Islamic Revolutionary Guard Corps Navy fast boats approached the seven US vessels at high speeds, closing within 150 yards (137 meters) before one of the US vessels fired 30 shots in two volleys, until they moved away, said Pentagon spokesman John Kirby. pmh/ec