LOS ANGELES (AP) - Robin Thicke tried to head it off with a lawsuit of his own. But two of Marvin Gaye's children have gone ahead and sued the singer over the hit song "Blurred Lines." The lawsuit - filed in Los Angeles - accuses Thicke and his collaborators of copyright infringement. The suit also targets music company EMI - claiming that it failed to protect their dad's legacy. The suits are filed by Nona Gaye and Frankie Gaye - and are part of their ongoing claim that Thicke's hit copies parts of Gaye's hit "Got To Give It Up." The suit seeks to block Thicke and collaborators Pharrell and T.I. from using elements of their father's music in "Blurred Lines" or other songs. Thicke has denied copying Gaye's song for "Blurred Lines," which has sold more than 6 million copies. Back in August, Thicke and his collaborators filed a case asking a federal judge to rule that the singers did not copy "Got to Give It Up" for their hit.