Aerial footage shows the extent of the flooding that has devastated Bihar
Up to half a million people are still stranded by flood waters in the Indian state of Bihar, aid workers say.
Monsoon rains caused the river Kosi to change course, severely affecting areas in Bihar not normally prone to floods.
The authorities have been criticised for failing to rescue flood victims well over a week after the scale of the flooding became apparent.
Meanwhile monsoon waters have been causing havoc in India's Assam state, as well as in Nepal and Bangladesh.
A non-governmental organisation (NGO) in Bihar, Mandan Bharti Jagriti Samaj (MBJS), told the BBC News website that 500,000 people still needed to be rescued.
"They are on the roofs of concrete buildings like schools... they are crying in the wilderness," the MBJS' Narenda Kumarjha said.
"People's dead bodies are floating in the water along with the corpses of cattle. People are forced to drink that same water."
In one of the worst affected districts, Supaul, some 280 villages are still completely cut off, the NGO said.
The BBC's Damian Grammaticas travelled on one small rescue boat in the district of Madhepura and saw submerged villages and railway lines. He says the flood waters stretched more than 100km (62.5 miles). "The rescue effort simply isn't very organised," he says.
People were being taken to dry areas and simply left to fend for themselves, our correspondent says.
Hundreds of villagers in Madhepura ransacked a food warehouse while police ran for cover, the Reuters news agency reports.
The looters also attacked government vehicles carrying food. "We cannot stop [these] incidents despite our best efforts," Bihar relief official Bijendra Prasad Yadav told Reuters.
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