Flash floods and landslides triggered by early monsoon rains have killed at least 560 people in northern India.

It has left tens of thousands missing and the death toll is expected to rise.

Houses and small apartment blocks on the banks of the Ganges, India's longest river and sacred to Hindus, have toppled into the rushing, swollen waters and been swept away with cars and trucks.

Thousands of military servicemen are involved in rescue operations.

Air force helicopters are plucking survivors, many of them Hindu pilgrims and tourists, from the foothills of the Himalayas.

About 33,000 people had been rescued so far according to the home ministry.

Railways were running special trains from the devastated areas to take people home.

Prime Minister Manmohan Singh has offered 200,000 rupees (€2500) to each of the families of those who have lost their lives and 50,000 rupees (€640) to the injured from his national relief fund.

He also pledged money to people who have lost their homes.

Mr Singh promised 10 billion rupees (€127m) to Uttarakhand, home to the gods in Hindu mythology and the hardest-hit state, for disaster relief.

So far, the rains have not hit the summer sowing season in northern India, as planting of rice, sugar, cotton and other agricultural produce is not yet in full swing.

Heavy rain early in the June-September season makes planting easier, but if flooding persists, stagnant water can delay sowing or damage early rice shoots.