A bullet hit an exterior window of the White House and a second bullet was found on the grounds, the U.S. Secret Service says.Washington\'s WRC-TV reported the rounds were discovered Tuesday morning and the Secret Service is investigating how they wound up there.The TV station said the Secret Service says it has not concluded the bullets are related to a Friday night incident in which authorities investigated what sounded like shots fired in the vicinity of the White House.Police have since been hunting for Oscar Ortega Hernandez, 21, in connection with that incident.