The party's supporters today went on rampage, protesting against the results of Monday's harmonised elections which saw Zanu PF winning two thirds majority in parliament.
The MDC did not immediately respond to the parliamentary figures but its presidential contender Nelson Chamisa, 40, said the presidential results were being faked.
Zimbabwean soldiers are circulating in the capital, Harare, and telling vendors and other people to leave the city center by noon.
Opposition supporters had marched to and from the gates of a compound where the Zimbabwe Electoral Commission had been announcing results.
The election, which pitched 75-year-old Mnangagwa against 40-year-old opposition leader Nelson Chamisa, was supposed to confirm the legitimacy of the post-Mugabe government and allow Harare to renew ties with the global community.
"They've rigged these elections". They also called for improvements in the counting procedure, saying the vote represented "a political watershed in Zimbabwe's history".
The deployment of soldiers and their beating of unarmed protesters tarnished incumbent President Emmerson Mnangagwa's attempts to rid Zimbabwe's derelict status after decades of repression under his predecessor, Robert Mugabe. "If President Chamisa wins this election then the people of Zimbabwe will have their government". "No amount of results manipulation will alter your will", he tweeted before the army was deployed.
At-least one person has been killed during the protests.
The opposition has alleged irregularities, saying voting results were not posted outside one-fifth of polling stations as required by law.
Mnangagwa's government has accused Chamisa and his supporters of inciting violence by declaring he had won.
However, many analysts have said they expect a win for Mnangagwa, a Zanu-PF veteran who replaced long-time president Robert Mugabe after he was ousted in a military coup in 2017.
"The strategy is meant to prepare Zim mentally to accept fake presidential results", he said, adding that he had won more votes than Mr. Mnangagwa. "We know that people will be beaten - especially in rural areas, like what they were doing before", said Harare shop worker Tracy Kubara, 26.
The EU mission also said it would deliver a more detailed assessment of how the election results are handled and announced at a later stage.
This has been seen as a pivotal election for Zimbabwe, with citizens expressing hope for change after years of economic malaise and political oppression under Mugabe.
Parliamentary results show Zanu-PF heading for a big majority.
European Union observers on Wednesday listed several problems in Zimbabwe's presidential and parliamentary election, including media bias, voter intimidation and mistrust in the electoral commission.
"The results are biased, trying to give the impression that ZANU has won", said Lawrence Maguranyi, 21, an MDC supporter and university student protesting at the party headquarters.