-LRB- CNN -RRB- -- One of Zimbabwe 's top officials blamed his country 's spreading cholera outbreak on what he calls `` a genocidal onslaught '' by Zimbabwe 's former colonial ruler -- Britain . Zimbabwean clinics have been overwhelmed by the cholera epidemic , according to aid organizations . `` Cholera is a calculated , racist attack on Zimbabwe by the unrepentant former colonial power , which has enlisted support from its American and Western allies so that they can invade the country , '' Information Minister Sikhanyiso Ndlovu told reporters . Britain ruled the country as a colony until 1965 . Ndlovu 's claims triggered quick and pointed reaction from Britain and the United States . In Washington , State Department spokesman Rob McInturff called Ndlovu 's accusations `` patently ridiculous . '' Referring to Zimbabwean President Robert Mugabe , McInturff said Friday that , `` Mugabe is clearly unwilling to take any meaningful action -LRB- to stop the cholera outbreak -RRB- . '' On Thursday , Mugabe said `` there is no cholera in the country . '' His spokesman later said that Mugabe was sarcastically ridiculing what he believes are Western designs to invade the country . Britain 's Africa minister , Mark Malloch-Brown responded by saying , `` I do n't know what world he -LRB- Mugabe -RRB- is living in , '' according to the British newspaper The Guardian . Malloch-Brown made the comment during a one-day trip to South Africa , where he visited a Johannesburg church housing 1,600 Zimbabweans who have fled their country , the newspaper said . `` There is a raging humanitarian crisis in Zimbabwe as well as an economic crisis and still there is no representative government able to lead the country out of this disaster , '' he said , according to The Guardian . Cholera has ravaged Zimbabwe , causing nearly 800 deaths and infecting more than 16,000 people , the World Health Organization says . The outbreak could surpass 60 000 cases , according to an estimate by the Zimbabwe Health Cluster , which is a group coordinated by the World Health Organization . View image gallery of Zimbabwe 's cholera crisis Â '' Cholera , a bacterial waterborne disease that causes diarrhea , dehydration and , if not treated , death in a matter of hours , is widespread in Zimbabwe but help is not . Like the general Zimbabwean economy , the country 's health delivery system is strapped , lacking modern drugs and machinery , while doctors and nurses have been striking for over a month . On Friday , the State Department issued a travel warning for U.S. citizens because of the cholera outbreak and violence that has flared as Zimbabwe 's economy has deteriorated . `` The public health system in Zimbabwe no longer provides even basic services due to a lack of staff , electricity , clean water , and medical supplies , '' the travel warning said . `` Americans who fall ill while in Zimbabwe may find it difficult to find treatment . '' At the State Department 's daily press briefing Friday , spokesman Sean McCormack said the situation in Zimbabwe will be one of the topics Secretary of State Condoleezza Rice will discuss when she visits the United Nations next week . `` The number of cases of cholera -- statements from Robert Mugabe notwithstanding -- is going up , not down , '' McCormack said . `` The crisis has not ended . People 's lives are in danger . '' Health experts say the Zimbabwean government can win the battle against cholera only if it imports adequate stocks of water-treating chemicals and disposes of refuse and sewerage properly . Watch shocking footage of Zimbabwe 's humanitarian crisis -LRB- Discretion advised -RRB- Â '' A Doctors Without Borders epidemiologist in Zimbabwe said , referring to the capital city , that `` the scale and sheer numbers of infection , especially in Harare , is unprecedented . '' He said the group has treated more than 11,000 patients since August and has 500 international and local staff members treating people in cholera centers across the country . He said the main reasons for the outbreak are poor access to clean water , uncollected garbage in the streets and burst and blocked sewage systems . `` The fact that the outbreak has become so large is an indication that the country 's health system ca n't cope , '' he said . Meanwhile , in his statement Thursday Mugabe said , `` I am happy to say our doctors , assisted by others and the World Health Organization , have now arrested cholera . So now that there is no cholera , there is no cause for war anymore . Let 's tell them -LRB- Britain and the United States -RRB- that the cholera cause does not exist anymore , if it was cause for war . '' The pro-government Herald , quoting presidential spokesman George Charamba , said Mugabe had been sarcastically reacting to `` calls for intrusive action '' against Zimbabwe from European leaders . Charamba said the country continues to want international assistance to combat the disease and has declared a state of emergency . The opposition Movement for Democratic Change , which rivals Mugabe 's ZANU-PF party , issued statements deploring the Mugabe government 's `` indifferent and casual approach '' to cholera and saying it was `` alarmed by Mugabe 's irresponsible and false remarks '' on Thursday . `` The ZANU-PF caretaker government is in a denial mode . The MDC believes that it is such careless and reckless statements that have not helped the situation , '' MDC said . `` We should be honest with ourselves and with the world . The truth is that cholera remains a major disaster in Zimbabwe , '' the MDC said . In his remarks to reporters in Zimbabwe , Ndlovu -- who said the country 's health system is working on the outbreak -- labeled the cholera outbreak `` a serious biological , chemical war force , a genocidal onslaught , on the people of Zimbabwe by the British , '' He also made reference to U.S. President George W. Bush and Rice : `` To the outgoing warmongers , please leave in peace and not in pieces . '' Ndlovu also slammed news outlets including CNN for what he called `` gunboat journalism . '' `` They take photos -LRB- of -RRB- people dying -LRB- in -RRB- the DRC and Darfur and say these are cholera victims from Zimbabwe , '' he said , making reference to the Democratic Republic of Congo and the Darfur region of Sudan .