Turnout has been high in Tanzania’s most competitive general elections, officials say, as a new opposition coalition tries to end the governing party’s 54-year grip on power.
In some areas, voting was extended to allow those still in queues to cast their ballots, officials added.
Opinion polls have put the governing Chama Cha Mapinduzi (CCM) party ahead, but the result is expected to be close.
Four opposition groups are backing one candidate, a former prime minister.
The BBC’s Tulanana Bohela reports from the main city Dar es Salaam that usually busy streets and markets are deserted, and large queues have formed at polling stations as people wait patiently to cast their ballots.
President Jakaya Kikwete, who is standing down after two terms, has called for peace ahead of the election, adding that “anyone who tries to cause trouble will be dealt with”.
CCM was formed in 1977 from a merger of two post-colonial parties and has effectively been in power since independence in 1961.
It has fielded Works Minister John Magufuli, 55, as its presidential candidate.
He is being challenged by Edward Lowassa, 62, who quit CCM after he failed to win its presidential nomination.
He is contesting the poll under the banner of the Ukawa coalition.
The unusually high turnout across the country suggests that Tanzanians believe the future is in their hands.
This is in contrast to previous elections when CCM was certain of victory because of a weak and divided opposition.