In the eastern state of Bihar, 62 people died in flood-related incidents as 2.8 million people were displaced, the United News of India reported.

Educational institutions in north Bihar were closed as water entered schools and other administrative buildings, the report said.

The situation in the districts of Sitamarhi, Bhagalpur, Gaya and Madhubani was precarious with people facing a severe shortage of food and water with road and rail transport services badly hit, it added.

In northeastern Assam state, five people drowned overnight taking the toll to 25, Assam relief and rehabilitation minister Bhumidhar Barman told AFP.

The 2,906-kilometre (1,816-mile) Brahmaputra river -- one of the longest in Asia -- also swept into the famed Kaziranga National Park renowned for its endangered one-horned rhinos, drowning a dozen animals, a park official said. No rhinos were killed.

"Army soldiers are continuing their rescue and relief operations," with authorities opening about 3,000 temporary shelters and distributing food and medicines, the minister said.

There are an estimated 1,855 rhinos at Kaziranga, situated 220 kilometres (137 miles) east of Assam's principal city of Guwahati.

"Herds of elephants, deer, wild buffaloes and rhinos from the park are migrating to adjoining hills ... with floodwaters inundating the sanctuary," making them an easy target for poachers, a warden said.

Another 25 deaths were reported from northern Uttar Pradesh state, mostly in house collapses, bringing the toll there over the weekend to 25.

Around 800 people have died in India since the onset of the monsoon in June according to a tally compiled from local officials and media reports.