Flood levels in Pakistan are expected to surge even higher along parts of the dangerously swollen Indus river.
The National Disaster Management Authority said "major peaks" are expected on Friday and next week in Punjab and Sindh provinces, the BBC reports.
The region's worst flooding in 80 years has already affected 14 million people and killed 1,600, according to the United Nations.
Doctors say malaria, diarrhoea and gastroenteritis are growing threats.
President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani are reported to have held an emergency meeting on Thursday night to review the government's much-criticised response.
Mr Zardari made his first visit to the disaster zone on Thursday in an effort to defuse public anger over his handling of the flooding, touring a relief camp at Sukkur in Sindh.
Opposition politicians said the trip by the president - who was widely condemned at home for not cutting short a trip to Europe while the floods crisis unfolded - was too little, too late