Helicopters are dropping aid to cut-off areas in the north

Continuing heavy rain in the area is hampering relief and rescue operations, the authorities say.

Helicopters are being used to drop food, blankets and other relief material in areas inaccessible by road.

Officials say nearly 500 people have died across Pakistan after a series of freak floods, landslides and avalanches over the past week.

Military and civilian relief workers have struggled to reach affected areas in North-West Frontier Province, where many roads have been blocked by landslides or snow.

Balochistan

Floodwaters are still to recede in parts of the southern province of Balochistan, where between 200 to 250 people have been killed - scores of them after a dam burst near Pasni, 650km (400 miles) from the provincial capital, Quetta.

In pictures: Flood misery

"The situation has not improved so far and rains continue to lash the area," provincial relief official, Raziq Bugti, is quoted as saying by the AFP news agency.

Thousands of troops have been deployed in Baluchistan in the relief effort.

Between 1,000 and 2,000 people are missing across the province and tens of thousands have been made homeless.

Officials are working to prevent the spread of waterborne disease.