Elsewhere markets were open and queues formed outside banks – a common sight in Zimbabwe due to the country’s chronic shortage of banknotes.
The opposition “are testing our resolve”, he said, “and I think they are making a big mistake”.
Mnangagwa previously said the opposition was to blame for the violence, though some worldwide observers criticized the military for opening fire on unarmed civilians.
According to the Zimbabwe Electoral Commission (ZEC) results, Mnangagwa’s ZANU-PF was cruising to victory after claiming 109 seats in a 210-seat parliament.
President Emmerson Mnangagwa’s party is poised to win a substantial parliamentary majority in Monday’s poll – the first elections since long-serving ruler Robert Mugabe was ousted.
Biti was finance minister in the 2009 to 2013 government, which saw Zanu-PF and opposition parties under the MDC alliance share power, and is said to be a respected politician in Zimbabwe.
The Zimbabwe Electoral Commission by law has until Saturday to release the final election tally.
With elections under Mugabe marred by fraud and often deadly violence, his successor President Emmerson Mnangagwa, 75, promised a free and fair vote and invited worldwide observers.
MDC supporters have ripped down a Mnangagwa billboard.
“What they have done is intimidate people in the rural areas saying, “we will kill you if you vote MDC” and so on and then the worldwide observers say this election was free and fair”.
Yet several of those observers, including a team sent by the European Union, have expressed doubts about how the elections have been conducted – noting concerns such as “intimidation of voters, [the electoral commission’s] lack of transparency in preparations, media bias and some problems around polling stations on election day”.
Under Mugabe, elections were often marred by fraud and deadly violence.
Once again, they had lost the battle for control of parliament and there seemed little chance that Nelson Chamisa – their charismatic party leader – could claim the presidency.
Many Zimbabweans looked to the vote as a launching pad for a return to the kind of global acceptance and relative prosperity that the country enjoyed in the first part of the rule of Mugabe, who took office after independence from white minority rule in 1980.
Mnangagwa also took to Twitter, calling for calm and urging patience before the results were announced.
Well, the country will be waiting to see what the ZEC Chairperson, Mr Priscilla Chigumba will be announcing in a couple of days.
It followed a surprise press conference at which he stunned observers and called for voters to reject ZANU-PF, his former party.
But Chamisa, a lawyer and pastor who performed strongly on the campaign trail, sought to tap into the youth and urban vote.
Observers from the Southern African Development Community called the elections “a political watershed in Zimbabwe’s history” but with some shortcomings, urging anyone with grievances to refrain from violence.
A United States team said the election “fell short of what was needed”, citing ZEC’s lack of independence, the use of food, fertiliser and seed to buy votes and the ballot design which gave President Mnangagwa an inexplicably prominent position.