Heavy rains have lashed a large area of Pakistan

About five villages were completely washed away and many houses collapsed after the dam burst near Pasni.

Officials in Balochistan province said up to 30,000 people had been affected by floods in the region.

Across the country, another 50 people have been killed in mudslides and house collapses triggered by two weeks of rain and snow.

Pakistan's President Pervez Musharraf and Prime Minister Shaukat Aziz have both expressed deep sorrow over the deaths across the country.

Swept away

Officials in Balochistan said the villages were swept away when rains breached the Shadikor dam near Pasni, 650km (400 miles) from provincial capital, Quetta.

Thousands of personnel from the army, navy, coastguard and civil emergency organisations have converged on the area amid fears that the casualty figures could rise significantly.

Many people have moved to higher ground or are standing on roofs waiting for help.

Helicopters are throwing aid in places they cannot land.

They have ferried to safety about 1,000 people.

However, one Baloch opposition leader, Kachkol Ali, said he believed 700 people were still missing

Mr Baluch told the BBC the greatest need was for tents, blankets, medicine and dry food.

'No let up'

Some cars, trucks and buses were swept into the Arabian Sea by the water when they were driving along a newly built highway in the Pasni region.

The rains have also washed away several bridges and part of a main road linking Pakistan's southern coast to the main cities.

Residents survey a house in Peshawar that collapsed in rains

"I have seen 15 bodies myself," a local resident Abdul Razzaq told the AFP news agency by telephone from the area.

Pakistan's meteorological department chief, Qamar-uz-Zaman Chaudhry, said some parts of the country had received the heaviest rain and snow in seven years, the Associated Press news agency reports.

The BBC's Paul Anderson in Islamabad says that for years Balochistan has seen nothing like this year's rains. It is a parched province that always faces near-drought.

Our correspondent says no let up in the wet weather is expected over the next two days.

Elsewhere, a television channel reported that 30 soldiers were missing after an avalanche in Terrah, a tribal region in north-western Pakistan.

The army confirmed it had lost contact with the troops and that a search operation was under way.

And officials in the Himalayan town of Gilgit say the Karakoram Highway that links Pakistan with China has been blocked by landslides at several points.