The death toll from Zimbabwe's cholera outbreak soared to 774 according to the UN agency, the World Health Organisation.
It said another 15,000 people were likely to be infected.
In Mozambique, officials said four people had died of cholera in a border area near Zimbabwe.
The cholera outbreak, coupled with chronic food shortages, has highlighted the economic collapse of the southern African nation and prompted calls for President Robert Mugabe's resignation from Western leaders and some within Africa.
Zimbabwe's government accuses enemies abroad of using the epidemic to try to oust Mr Mugabe, and blames Western sanctions for ruining the once relatively prosperous southern African country.
Zimbabwe's information minister Sikhanyiso Ndlovu said on Tuesday that the cholera situation was under control.
Court orders police to find activist
The Zimbabwe High Court on Tuesday ordered police to find missing rights activist Jestina Mukoko, a former journalist and head of the Zimbabwe Peace Project.
He was taken away at gunpoint in Harare on 3 December.
Police have said she is not in their custody.
About 50 lawyers and rights activists marched in central Harare on Tuesday and handed a position to the speaker of parliament expressing accusing the government of violating human rights.
Scores of opposition activists were abducted and killed in the run-up to a June presidential run-off election.
Opposition MDC party leader Morgan Tsvangirai boycotted the vote after the attacks, allowing Mr Mugabe to win the one-candidate poll.