Zanzibar set to hold presidential vote on March 20

Tanzania's semi-autonomous Zanzibar region will hold a re-run of its disputed general election on March 20, its electoral body announced on Friday, despite opposition calls for the poll to be scrapped on the grounds it might spark violence.

A previous ballot on Oct. 25 was annulled on grounds of fraud.

Tanzania has been one of Africa's most politically stable nations but Zanzibar has been a hotbed of opposition to central government, with strong secessionist and Islamist voices. Votes on the islands are usually closely fought and often disputed.

The Zanzibar Electoral Commission said it would hold presidential, legislative and local government elections on the same day.

"There will be no campaign rallies ... the same candidates who were picked in the previous polls will stand in this election," commissions chairman Jecha Salim Jecha said.

President Ali Mohamed Shein of the ruling CCM party stood in the previous polls against his main challenger, Seif Sharrif Hamad of the main opposition Civic United Front (CUF) party.

There were other presidential candidates from smaller parties, but elections in Zanzibar have always been a tight two-horse race between CUF and CCM, which has ruled mainland Tanzania for more than five decades.

The CUF which says it won the Oct. 25 vote has warned that violence could erupt on the Indian Ocean archipelago if fresh elections are held. It says a dialogue to form a government of all parties under its leadership should be held rather than a new vote.