NEW DELHI, India (CNN) -- Hundreds of Indian army troops were using helicopters and boats Wednesday to deliver supplies and rescue villagers stranded by the worst flooding in decades, after the Kosi River breached an embankment in Nepal to the north.
The death toll in the hard-to-reach Bihar state in northeastern India has been difficult to determine. Bihar emergency management official K.K. Agarwal confirmed 10 deaths to CNN on Wednesday, but the news agency Press Trust of India (PTI) reported 55.
Phone lines and electricity are out in the flooded areas.
In the Supaul district city of Birpur, Mohd Rauffudin's hopes were fading. He told IBN -- a CNN partner station in India -- that while he was trying to stay afloat, he lost contact with his wife and children, as well as his nine brothers and his parents.
"I wish the help had reached (us) on time. That way at least my children could have been safe," he said.
A woman who called herself Ruby told IBN her baby has been sick for four days, she can't reach medical help and she has lost track of her family.
"My child is so ill. I cannot do a thing about it. I wonder what I did wrong that my child must suffer," the mother said.
The flooding began when the river burst through an embankment in Nepal more than a week ago, swallowing villages and destroying about 225,000 homes, officials and UNICEF India said.
Water flowed so forcefully from the breach that the river changed course, making a new channel about 75 miles (120km) east of its river bed, flooding areas unaccustomed to water that high. Watch survivors find safety on roofs »
Agarwal said the disaster affected about 2 million people and 725 villages in Bihar, India's poorest state. Ninety-five relief shelters had been set up, 44 health-care camps and 22 shelters for animals, he said.
Army spokesman Lt. Col. A. K. Mathur said 400 troops were involved in rescue operations, and the military had dispatched at least 20 rescue boats. Three army helicopters were dropping thousands of food packets, he said.
PTI reported earlier in the day that bad weather had prevented Indian air force choppers from conducting relief drops in the worst-hit districts of Bihar: Supaul, Saharsa, Araria and Madhepura.
Officials told CNN it was the worst flooding in Bihar in 80 years. Watch more on people stranded »
The Kosi is known to Indians as the "River of Sorrow" because of its flooding during the monsoon season, which lasts from June to September. The river flows into the Hindu-revered Ganges River.
Video has shown residents huddled atop low-rise buildings, standing in waist-high water in the streets and trying to escape in boats. The flooding has submerged roads and railway tracks, and cut off electricity.