By the BBC's
Joseph Warungu

Tanzania's ruling Chama Cha Mapinduzi (CCM) has mounted a huge campaign on the island of Pemba. The town's main streets and alleys are draped in huge green posters, the traditional colour of CCM, depicting a smiling Amani Karume who hopes to inherit the seat his father occupied in the 1960s as president of Zanzibar. Next to Mr Amani is the image of a robust-looking Benjamin Mkapa who is also hoping for another five-year term in office as president of the union government.

The posters and billboards meander through the green Pemba landscape deep into the 21 constituencies on the island.

During the previous elections, the opposition won all the 21 seats. On the other hand, the ruling CCM won the presidency narrowly. But the loss of its political control over half the territory left a bitter taste in the mouth. The party is determined to bag at least one face-saving seat if not more. Tanzania's President Mkapa attended big campaign rallies to drum up support for CCM and its Zanzibar candidate.

But CUF is not cowed either. Its leader and presidential candidate, Seif Shariff Hamad, was upbeat saying his party will win 90% of the vote and that come 1 November it will be he - Maalim Seif as they call him - who will take the oath of office to lead Zanzibar.

The bitter rivalry between the two main parties has raised a lot of fears and fanned all sorts of rumours on this island. I spoke to a group of CCM women here who fear the opposition might rush to cast their votes and bar other people from reaching polling centres.

The opposition denies the claims and instead accuses CCM of perpetrating state harassment and intimidation.

At the moment, the situation in Pemba appears quiet, with occasional campaign vehicles blaring out messages. Small groups of young men huddle together in the evenings to discuss politics. What happens after Sunday, however, is anyone's guess as neither CCM nor a CUF victory will be easy to digest.