Zanzibar's President Amani Karume has been sworn in after being re-elected. Mr Karume rejected opposition claims of fraud in Sunday's election in the semi-autonomous Tanzanian islands. The poll was marred by violence by police and members of both parties, but international observers described the vote as generally free and fair. Civic United Front opposition candidate Seif Hamad rejected the results and promised protests. Police cordoned off the CUF headquarters on Wednesday.