Flash floods and landslides unleashed by early monsoon rains have killed at least 560 people in northern India and left tens of thousands missing, officials said on Saturday.

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

Thousands of military servicemen are involved in rescue operations, with air force helicopters plucking survivors. About 33,000 people had been rescued so far this week, the home ministry said. Railways were running special trains from the devastated areas to take people home.

The rains had eased on Saturday but more rain is expected early next week, complicating the task of rescuers. Rain will fall from Monday onwards in many places in the Himalayan foothills, said a weather official who sought anonymity.

As many as 150,000 people were airlifted from the reach of the floods, said Dinesh Malasi, a rescue official at Dehradun, the state capital, with 60 helicopters pressed into the task.