Zimbabwe's Constitutional Court confirmed President Emmerson Mnangagwa's disputed 30 July election victory today, dismissing an opposition challenge that had held up his inauguration, which will now be held on Sunday.

In a unanimous ruling of the nine judges of the country's top court, Chief Justice Luke Malaba said Nelson Chamisa, who leads the opposition Movement for Democratic Change (MDC), had failed to prove allegations of fraud during the presidential vote.

"Emmerson Dambudzo Mnangagwa is duly declared the winner of the presidential elections held on the 30th of July 2018," Mr Malaba said in his ruling.

The election, in which Mr Mnangagwa and Mr Chamisa were the main contenders, was touted as a crucial step towards economic recovery and shedding Zimbabwe's pariah reputation, but instead has left the nation polarised.

An army crackdown in response to post-election violence by opposition supporters left six people dead on 1 August, recalling the heavy-handed security tactics that marked the 37-year rule of Robert Mugabe, who was removed in a coup last November.

Mr Mnangagwa now faces the challenge of persuading the international community that the army crackdown and lapses in the election process will not derail his promise of reforms needed to fix the economy.

The president called for peace on his Twitter feed, after the ruling was delivered.

"Nelson Chamisa, my door is open and my arms are outstretched, we are one nation, and we must put our nation first. Let us all now put our differences behind us," he said.

Finance minister Patrick Chinamasa said that Mr Mnangagwa would be inaugurated on Sunday.

MDC Secretary General Douglas Mwonzora told reporters outside the court that "whatever we do as MDC we are going to act within the law... We want Zimbabweans who want to demonstrate to be allowed to demonstrate".

Police blocked roads around the court, a 19th century British colonial building just opposite Mr Mnangagwa's offices in central Harare.

Vehicles carrying water cannon reappeared on streets near the court house while riot police patrolled the city centre in groups.