Pakistani authorities are struggling to stop their biggest lake from bursting its banks after last-ditch attempts to lower water levels failed, a media report said.

The Manchar Lake in Sindh province is dangerously full after record monsoon rains that inundated a third of Pakistan, BBC reported.

Three breaches of the lake's banks so far - to protect areas downstream - have displaced over 100,000 people.

But it could still overflow and rescue teams are racing to evacuate many more people who remain at risk of drowning, BBC reported.

Floods in Pakistan have affected some 33 million people and killed at least 1,314 persons, including 458 children, Pakistan's National Disaster Management Agency said.

Estimates suggest the floods have caused damages amounting to at least $10 billion.

Sindh province accounts for half of the country's food supply, exacerbating fears that many will face serious food shortages in a country already struggling with an economic crisis.

On Sunday, officials breached Manchar lake after it had flooded two rural towns, in the hope that it would prevent it from further bursting its banks and inundating more densely-populated areas.

The move affected an estimated 400 villages - a total of 135,000 people. The decision to deliberately flood some villages is a controversial one - the lake straddles two districts, Dadu and Jamshoro, both home to hundreds of thousands of people and about 80% of the region is underwater, BBC reported.

Villagers affected by the deliberate breach were warned to evacuate. But local sources say not everyone was taken to safety in time - some didn't want to leave their homes or livestock, a lifeline for many in rural communities, and there are few places for them to go. (AA/IANS)