Ciudad Juarez , Mexico ( CNN ) -- Two U.S. citizens -- a mother and her son -- - have been killed in the violence-plagued Ciudad Juarez , Mexico , authorities said . A mother and her son were killed in an attack . They were among those killed in the attack in Ciudad Victoria . Authorities released the victims Monday . Police have not determined a motive .
A mother and her son were killed in an attack . They were among those killed in the attack in Ciudad Victoria . Authorities released the victims Monday . Police have not determined a motive .