Villages submerged as more floods sweep through Pakistan

At least 1,200 people have already died in the first recent deluge last week. Fresh rain in the hardest-hit north-west of the country has threatened to overwhelm a major dam and unleash a new torrent.

Rescue and aid for two million people has been delayed by swamped roads, washed-out bridges and downed communication lines. Survivors have complained about lack of government action.

Other countries, including Britain, have pledged help for Pakistan which is also struggling to control a wave of Taliban attacks.

About 3,000 people were marooned in the Kot Addu area of southern Punjab province after the water breached a protection bank, forcing the army to stage an evacuation using boats and helicopters.

Punjab is Pakistan's most populous province, and home to many of its largest farms.

Many villages in the eastern province's Layyah, Taunsa Sharif, Rajan Pur, Dera Ghazi Khan and other areas had been inundated.

In the north-west, new downpours yesterday added to the misery of the worst flooding in generations. Rising water levels at Warsak Dam, the country's third biggest, prompted disaster officials to ask residents in the northern outskirts of Peshawar to leave their homes.

The north-west is the centre of Pakistan's battle against al-Qaida and the Taliban. Alongside military and police operations, the government – with the support of the West – has tried to improve its services and living standards there to blunt the appeal of militancy.

Britain has pledged another 5m in aid, with Britain's Department for International Development already contributed 5m to a UN fund.