The United Nations has said 3.5 million children in Pakistan's flood zones are at risk of catching water-borne diseases. <br /><br />According to the UN, six million people in all could contract diarrhoea and dysentry and the World Health Organization is bracing for cholera.<br /><br />Some 20 million people near the overflowing River Indus have been affected by Pakistan's worst floods on record.<br /><br />The floodwaters have covered large areas from Kyhber-Pakhtunkhwa in the Nort to much of the country's agricultural heartland of Punjab and Sindh in the South.<br /><br />The floods cover an estimated 160 square kilometres of Pakistan, about one fifth of the country.<br /><br />Even in normal times it is difficult to get around much of mountainous northwest Pakistan. The floods have left many areas near the towns of Al Puri and Karora inaccesible. <br /><br />Al Jazeera's Sohail Rahman took the road north from Swat Valley and found whole communities cut off.
