Monsoon systems were weakening after three weeks of torrential rains brought devastating floods that have left at least 1,400 people dead in the country's worst natural disaster, with survivors hitting out at the government's slow response.

The floods wiped out villages, farmland and infrastructure, and OCHA, the United Nations' aid coordination body, said that more than 650,000 homeless families were still without basic shelter.

At a camp for 3,000 displaced people in the south of Punjab province, most sat in crippling heat, batting away mosquitoes. Concerns were growing about cholera and typhoid, while many were suffering from stomach problems.

Half were children, an army official told AFP, with a few crammed into tents furnished with straw cots, while others were held back by soldiers as they attempted to reach medical and food supplies arriving by helicopter.

The UN last week launched an immediate appeal for 460 million dollars, and said on August 18 that funding had reached 54.5 percent of this target, though that included pledges that were yet to turn into cash.

AFP