President Amani Abeid Karume on Wednesday inspected a military guard of honour and was presented with a 21-gun salute after Zanzibar's Chief Justice Hamid Mahmoud administered the oath of office to head the legislature in the semi-autonomous Indian Ocean archipelago.
"It is a great achievement of democracy," Karume said, as supporters, anti-riot police and the merely curious looked on.
"The opposition must accept defeat and respect the people's choice."
Later, members of security forces raided homes in an opposition stronghold on the second island, Pemba, breaking down doors, looting valuables and beating residents, according to witnesses who spoke on the condition of anonymity as they feared retribution.
The witnesses said villagers in parts of Pemba had fled their homes and unconfirmed reports said some 3000 people were living rough in the bush to avoid the security forces.
"The opposition must accept defeat and respect the people's choice"
Amani Abeid Karume,
But Regional Police Commander Ameir Juma Ameir dismissed the reports as "propaganda," adding that villagers fled into the bush after chasing a member of security forces who is now missing.
Seif Shariff Hamad, candidate of the main opposition Civic United Front said five supporters died on Pemba during protests on Tuesday. A member of the government security force said four of his colleagues were killed on Pemba.
Karume, of the ruling Chama Cha Mapinduzi, won 53.2% of the vote, while Hamad had 46.1%, according to electoral chief Massauni Yussuf Massauni.
Of the 50 seats up for election in the House of Representatives, the Chama Cha Mapinduzi was declared the winner of 30 seats and the Civic United Front won 19.
Results for one seat were nullified because of irregularities.
The opposition says several
supporters died in the riots
Hamad again rejected the results on Wednesday and called for independent investigations of the election results and for international mediation in Zanzibar to prevent a crisis.
He vowed not to cooperate with Karume's government and has pledged to launch a civil disobedience campaign similar to the one that toppled the government in Ukraine last year.
The European Union backed calls for an investigation into alleged electoral flaws. "The EU considers it important that all parties should act with restraint at this sensitive time, and pursue any grievances peacefully and through established channels, and in accordance with local laws and procedures," a statement said.
Karume dismissed the opposition's threats, saying, "The choice is irreversible. It is the choice of democracy. It is the choice of the people."
The socialist Chama Cha Mapinduzi, or Revolutionary Party, has ruled Zanzibar for more than 30 years. The Civic United Front, which promises privatisation and wholesale economic reform, claimed it was robbed of victory by violence and fraud in elections in 1995 and 2000, and again accused Chama Cha Mapinduzi of fraud in the latest vote.