Zimbabwean police have blocked the main opposition Movement for Democratic Change party from holding its 19th anniversary celebrations this Saturday due to a cholera outbreak that authorities say has claimed at least 25 lives in the southern African country.

Initially detected in the capital Harare, authorities said the disease was spreading fast to other parts of the troubled nation.

Despite having sanctioned the event in which the MDC was reportedly planning a mock inauguration of its leader Nelson Chamisa who claimed victory in the July 30 polls controversially won by President Emmerson Mnangagwa of the ruling Zanu PF party, police made a U-turn on Wednesday evening, banning the planned celebrations.

"Considering the magnitude of people that will be flocking from all over Zimbabwe on your anniversary celebration day, it is not advisable for thousands of people to gather in an area where there is an outbreak of a contagious disease. Meanwhile, the intended celebration is not sanctioned," police said in a letter to the MDC.

Zimbabwean authorities have declared a state of emergency in the capital Harare following the cholera outbreak that has more than 3 000 people being infected with the disease.

However, the MDC was quick to point fingers at Mnangagwa's administration accusing it of using the cholera outbreak as an excuse to ban its activities following the disputed elections.

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Spokesperson of the MDC, Jacob Mafume, told News24 that the government banned its event despite the cholera scourge having been contained in Harare's populous suburbs of Glen View and Budiriro.

"We are all aware that the regime is running scared of our gatherings; they have allowed life to go on as usual as far as it pertains to activities that are being done by the current Zanu-PF government.

They have defined public gatherings as those gatherings where the MDC is gathering," said Mafume.

Mafume said his party was taking stock of the ban before informing its party's structures on the way forward.

However, the party later issued a statement saying it was postponing the event to a later date.

The cholera epidemic has also forced the country's biggest institution of higher learning, the University of Zimbabwe, to cancel a graduation ceremony that was set to be presided over by President Mnangagwa on Friday.