Floods triggered by monsoon rains have killed at least 79 people and displaced two million others in eastern India.
Entire villages were washed away in the state of Assam, when the Brahmaputra river breached its banks.
The Indian army has been deployed to help flood victims. Major General R.N. Nair told reporters on Monday, "we are continuing to supply food packages and water, medical aid is being provided in almost all parts of the [Guwahati city] district. Our helicopters have been pressed into action to drop food packets to those who have been marooned."
Indian Prime Minister Manmohan Singh flew over the flooded areas on Monday and said "the people of Assam are facing one of the worst floods in recent times." He announced $1,800 compensation to families whose relatives died in the floods and an additional $90 million in federal help to the state government.
The prime minister also told reporters that steps were being taken to immediately restore railway service in affected areas to ensure supply lines remained open.
Authorities said at least 500,000 people have taken shelter in relief camps.
Doctors have set up mobile health clinics to treat flood victims and prevent the outbreak of water-borne diseases.
Officials said most of Assam's Kaziranga National Park, famous for its one-horned rhinos, was submerged - with animals forced to seek higher ground.
The state of Assam is known for its hilly tea-growing areas.
The flooding in eastern India comes as the remainder of the nation deals with lower than expected monsoon rains, raising concerns about India's agricultural output.
Some information for this report was provided by Reuters.