MUSCAT // Oman's health ministry has reported the Gulf nation's first three cases of swine flu. The ministry adviser Jaafar ben Ali said today the cases were diagnosed in three students who had been studying in the United States. He said their symptoms appeared after arriving in Oman on June 13. All have been sent home after treatment. The World Health Organization said as of today that its Middle East member countries have informed it of more than 100 confirmed cases of infection with the virus.