Pakistani health officials have reported an outbreak of waterborne diseases in areas hit by recent record-breaking floods, as authorities step up efforts to ensure the provision of clean drinking water to hundreds of thousands of people who lost their homes in the disaster.

Diarrhoea, skin diseases and eye infections are spreading at relief camps set up by the government across the country. More than 90,000 diarrhoea cases were reported from one of the worst-hit provinces, Sindh, in the past 24 hours, according to a report released by the health officials on Thursday.

The latest development comes a day after the government and the World Health Organization raised concerns over the spread of waterborne diseases among flood victims.

Pakistan blames climate change for unusually early and heavy monsoon rains, which since June have caused flash floods that have killed nearly 1,200 people and affected 33 million people. About a million homes have also been damaged or destroyed.