Military specialists have blown up dykes in central Pakistan to divert swollen rivers and save cities from raging floods that have killed nearly 500 people in Pakistan and the Himalayan region of Kashmir and affected over two million others.

The breaches at the overflowing Chenab River were done overnight as floodwaters reached Multan, a city famous for its Sufi saints.

Pakistani troops have been using helicopters and boats to evacuate marooned people since September 3 when floods triggered by monsoon rains hit Pakistan and Kashmir, which is divided between Pakistan and neighbouring India.

Pakistan's military said it was still evacuating people and air-dropping food.

So far, 274 people have been killed in Pakistan and Pakistan-controlled Kashmir, while 200 have died in India-controlled Kashmir.