Up to 50 women in Zanzibar have been divorced for taking part in the recent Tanzanian elections against the will of their husbands, according to lawyers and women's rights campaigners.

Mzuri Issa, coordinator of the Tanzania Media Women's Association (TAMWA) in the semi-autonomous Zanzibar archipelago, said 47 women were divorced for voting contrary to their husband's orders in a tightly-fought ballot that remains undecided.

Issa added some women did not take part in the election for fear of being divorced or for fear of violence, while others complained that they were forced to cast ballots for candidates they did not support.

The divorces were confirmed by the Zanzibar Female Lawyers Association (ZFLA) and the Mwanakerekwe district Kadhi court in Zanzibar.

"Some of the women were not allowed by their husband to vote but those who refused to see their right trampled on were either divorced or abandoned," Issa told reporters.

Tanzania's ruling Chama Cha Mapinduzi (CCM) party, which has governed the East African country since independence in 1961, faced its toughest challenge in years in the October vote after opposition parties united for the first time for one candidate.

But the election was overshadowed by a political crisis in Zanzibar which has a primarily Muslim population of 1.3 million people and has its own parliament and president.

The election commission annulled the vote for the island's president, citing "gross violations".

The main opposition Civic United Front (CUF) rejected the move, saying it had won that poll and a fresh presidential election is scheduled to be held again in January or February next year.

Some women complained that their husbands had divorced and abandoned them with children because they had supported CCM while their husbands supported the opposition, activists said.

"I thought it was just normal and free in a democracy to differ in politics. But unfortunately, my husband was adamant to the end and decided to divorce me. He has even decided not to bring basic needs to our young children," a woman speaking on condition of anonymity told the local Daily Newspaper.