Opposition protesters fought running battles with police on the semi-autonomous Indian Ocean islands of Zanzibar and the death toll since Friday rose to at least 37.
The violence was worst on Pemba, the smaller of Zanzibar's main islands, where witnesses said at least 24 people had been killed. These including four members of the security forces who were hacked and stoned.
A policeman was also beheaded in Pemba on Saturday.
Pemba residents reported gunfire late last night as opposition demonstrations to protest against alleged fraud in elections last year continued.
A team of Red Cross workers arrived on Pemba earlier yesterday and began moving the dead bodies to a hospital.
A doctor on the islands said 13 corpses had already been recovered and that the work would continue today if the fighting died down.
Zanzibar President Mr Amani Karume blamed the violence on opposition activists and said the police would find and capture those "responsible for the chaos".
"The arm of the law is long and it will reach them wherever they are," he said in a televised address.
Reuters