At least 240 people are now known to have died in floods affecting India, Bangladesh and Nepal, where millions of people face continuing misery.
The floods in northern India and Bangladesh have not receded
Hundreds of thousands of people in the Indian state of Bihar are short of food and isolated while rescue services are struggling to deliver aid.
Officials in the state of Assam fear malaria and encephalitis epidemics.
The waters in southern Nepal have receded but bridges remain down and roads are cut in several places.
Aid agencies have appealed for international help, with Save the Children estimating that almost 14 million people in India and another seven million in Bangladesh are feeling the impact of the floods.
In Bihar, Indian air force helicopters are flying in flour, sugar and milk powder to stranded villagers.
But ten million people are affected by the floods there with perhaps a million camping in the open and an estimated 70,000 homes submerged or washed away.
Bihar's chief minister has ordered his cabinet colleagues to the flood-hit areas to oversee aid efforts.
"They will camp in areas assigned to them to supervise relief operations until the situation normalises," Nitish Kumar said.
THE AFFECTED AREAS
India: 12 million people stranded, mostly in Bihar, Uttar Pradesh and Assam
Bangladesh: Seven million people marooned
Nepal: Thousands of people displaced in the south
Many communities may not be reached until the water levels fall.
The latest victims of the Bihar floods either drowned or were crushed by falling buildings.
In Assam, Chief Minister Tarun Gogoi has told Reuters news agency he is "really worried" about an outbreak of disease as waters recede and temperatures soar.
In Uttar Pradesh, two million people are affected and officials say 0.25m acres of crops have been damaged.
Further downstream, the waters continue to rise in Bangladesh too.
The government there says it has enough stocks of food and medicine and foreign help is not needed.
While fields and villages in southern Nepal are drying out, the monsoon season is far from over, the BBC's Mark Dummett reports from Janakpur, near the border with India.
THE ASIAN MONSOON
Monsoon winds blow north-easterly for one half of the year, and from the south-west for the other half
South-westerly winds bring the heavy rains from June to Sept
Winds arrive in southern India six weeks before the north west
Annual rainfall varies considerably
Overnight lightning drove some people to leave their houses and spend the night in sturdily built school classrooms, he says.
The main problem is that many roads in the area have been cut and bridges have been washed away.
It is proving very hard for aid agencies and the government to take help to the most needy people.
They have distributed some food supplies to some communities, but the people there - many still living in their damaged mud and thatched homes - complain it is not enough.
Floods occur in southern Nepal every year, our correspondent adds, but the ferocity of these ones have taken everyone by surprise.