More than 80 people have been killed in monsoon floods in northeastern India and nearly half a million people have fled their homes. Prime Minister Manmohan Singh says relief camps have been set up across Assam state. Singh said Monday after surveying flood-hit districts that air force helicopters were dropping food packets and drinking water to marooned people. Army soldiers have rescued villagers from rooftops, according to a report of the Associated Press. State officials say 81 people have been killed over the past four days. Most of them were swept away when the Brahmaputra River overflowed its banks and flooded villages. Sixteen people were buried in a landslide triggered by the rains. Assam suffers flooding almost every year but this year's disaster is its worst in at least a decade.