Violence has flared at the start of Zimbabwe's bitterly contested presidential elections.
A dozen people were injured when police fired tear gas and rubber bullets at voters trying to force their way into a polling station in the western Harare township of Kuwadzana.
A crowd of 3,000 people tried to rush the building in what appeared to be a protest at the slow pace of the work of polling officials.
Throughout the election campaign, human rights workers have accused President Robert Mugabe's Zanu-PF of sponsoring militants who have attacked opposition supporters and their offices.
Police broke up several opposition rallies and arrested dozens of opposition leader Morgan Tsvangirai's supporters.
Civic groups, opposition supporters and witnesses said such violence and intimidation continued on the first day of voting, with militants breaking into one polling station and stealing voting materials.
Militants also took over two polling stations and at another, ballots arrived already marked in favour of Mugabe.
But the main problem appeared to be the snail's pace of voting, particularly in urban areas where Tsvangirai's Movement for Democratic Change (MDC) is seen as strongest.
In the capital, Harare, only 20 people were voting per hour at many stations, frustrating thousands of people waiting outside in hot weather.
Polling officials at one station took a two-hour lunch break, despite raucous complaints from voters.