The opposition Movement for Democratic Change has comfortably retained two parliamentary seats in the Zimbabwean capital after by-elections at the weekend.
People waited their turn to vote
President Robert Mugabe's party had been desperate to win a seat in Harare, which has long been an opposition stronghold.
The weekend polls were described as largely peaceful by diplomats and the police, but marked by strong opposition claims of voter intimidation and ballot fixing.
State radio said the MDC won 12,548 votes in the Kuwadzana constituency, against 5,002 votes for the ruling Zanu-PF. In the Highfield constituency, the opposition won 8,759 votes against 4,844 for Zanu-PF.
President Mugabe's party, with 95 seats, enjoys a comfortable majority in the 150-strong parliament, but is five seats short of a constitution-changing two-thirds majority.
Earlier on Monday, a strong police presence was reported outside State House and at roadblocks around the capital.
Tension has been rising ahead of a deadline of 31 March given by the opposition to the government to meet its demands over human-rights abuses and democracy, or face peaceful mass action.
At lunchtime on Monday, MDC vice president Gibson Sibanda was arrested by the police in Bulawayo in connection with strikes called by the party a fortnight ago.
The EU accuses Mugabe's government of arresting opponents
Chief police spokesman Wayne Bvudzijena said Mr Sibanda was arrested for "attempting to subvert a constitutional government".
At the end of polling on Sunday evening, MDC leader Morgan Tsvangirai issued a strong statement saying events had come to "the countdown to the final reckoning".
And he said the country could soon expect a "final push for freedom".
The recent strikes brought the capital and other urban centres to a halt in a huge show of support for the opposition.
A crackdown on MDC members followed, with many people being arrested, and there were widespread reports of the beating and torture of opposition supporters.
The run-up to the polls had already seen tensions rising following the anti-government strike last week.
Zanu-PF and the MDC exchanged allegations of violence during campaigning which human rights groups say left hundreds of people injured.
On Friday, the European Union condemned "unprecedented government-sponsored violence" against the opposition in Zimbabwe.
It said the Zimbabwean people had a constitutional right to protest peacefully and called on the government to respect that right.
But during the voting, police said they had received no reports of violence and the election authorities insisted there were no irregularities.