"An American Negro who has served as an infantryman in South Vietnam asserted here today that it was United States practice 'to put Negroes, Puerto Ricans and poor white people who are considered expendable into combat outfits.'

The American, David K. Tuck of Cleveland, had said in testimony before a new session of the so-called International War Crimes Tribunal yesterday that most of the soldiers in American combat units in Vietnam were Negroes.

Discussing the testimony in an interview today, he said: 'As long as the black people in the United States are denied their rights, they shouldn't have to accept the duties and obligations of citizenship because they are no treated as citizens.'

The second session of the tribunal, which was founded by Bertrand Russell, the British philosopher, convened last Monday to consider 'the extent to which America is already guilty of genocide' in Vietnam.

Ralph Schoenman, the American secretary of Lord Russell, returned here Friday night after a fifth European country refused to admit him. He is awaiting a hearing on an appeal against confiscation of his American passport."