Flood survivors in Pakistan are not only facing the threat of serious illness with a lack of doctors and medication, but food shortages as well, as the water has also washed away crops and submerged hundreds of thousands of hectares of fertile farm land.

The United Nations has so far received less than half of the $459 million in immediate aid funding it appealed for last week. Another $43 million has been promised. On Tuesday the World Bank announced it would redirect $900 million of its existing loans to Pakistan to assist in the flood recovery effort.

Canada has pledged up to $33 million.

Meanwhile, thousands of people await medical assistance, emergency shelter and food supplies and anger continues to grow over the government’s perceived sluggish response to the crisis. Aid agencies and the British government have complained the international community hasn’t stepped up to provide the money needed to help those in desperate need of basic life-saving necessities, including clean drinking water, food, emergency shelter and medicine.

The torrential downpours and the subsequent flooding has so far killed approximately 1,600 people and left as many as 20 million people in need of immediate assistance. The nation’s northwestern Sway Valley region has been hit particularly hard, where water has washed away entire villages and destroyed bridges and other key infrastructure, including hospitals and schools. Large swaths of the Punjab and Sindh provinces are also submerged.

Authorities warned Tuesday that the Indus River could burst its banks again.

Water-borne illness poses a great threat and the UN said cases of diarrhea are rising, increasing the risk of malnutrition.

Looting and protests over food shortages have also been reported in Punjab. The water washed away approximately 700,000 hectares of wheat, sugar cane and rice crops. Fruit crops have also been destroyed. Food prices have spiked since the flooding began more than three weeks ago.