Thousands of people were marooned in Bihar after the Kosi river breached its banks upstream in Nepal, flooding villages and towns in many areas across the state. The floods have claimed 45 lives so far.
Floodwaters entered new areas on Tuesday and have affected two million people so far in Supaul, Araria and Madhepura districts.
Chief Minister Nitish Kumar said that a breach in the Kosi embankment near Kusaha in Nepal had forced the river to change its course, for the first time since the 1950s.
The chief minister said it was not a normal annual flooding, but a catastrophe.
Most of the marooned people have been without food and water for five days. Despite the government maintaining that it has air dropped relief material and set up relief camps, crowds of displaced people perched on embankments were seen protesting against inadequate government help.
"This time, the flood has been caused by a two km breach in the embankment of river Kosi. The government has initiated moves to plug it," Ajay Naik, principal secretary in the water resources department, said.
Naik said that authorities were working to prevent further widening of the breach and channels would be dug to direct the water back to the main river bed.
"The Nepal government is helping the Bihar government to plug the breach," Naik said.
According to official sources, the Hindustan Steel Construction Ltd company has been given the task to restore flow of the Kosi along its original course.
Bihar Disaster Management Minister Nitish Mishra told IANS that one million people were marooned in Supaul, Madhepura and Araria districts and had to be evacuated to safer places soon. He said thousands have been evacuated in the three districts and taken to relief camps. But more relief camps had to be set up.