"Along the route, I saw thousands of villagers running towards the town. Some were on foot, some on their bicycles. Some were taking their cattle. Villagers have loaded their entire life's acquisitions on ox-carts and trying to escape the waters."
Our correspondent says people have taken shelter at the railway stations and higher stretches along some of the roads.
Many angry villagers complained they had received no food or aid and did not know where they could take shelter.
"Every where you look, there is water. Houses are submerged, shops are under water and people can be seen wading through water."
Meanwhile, officials say a massive rescue and relief operation is underway.
At least 124,000 people have been evacuated to safer grounds.
Officials said 725 villages were badly affected by the floods and 106 relief camps had been set up in the area.
Army and air force helicopters continued to provide aid to the flood-ravaged parts and 600 boats were helping with the relief and rescue work.
Prime Minister Manmohan Singh and the president of the governing Congress Party, Sonia Gandhi, flew over the flood-affected area on Thursday by helicopter to get a first-hand view of the devastation.
The floods have washed away roads and railway tracks, and water and electricity supplies have been affected in many areas.
Many people say they have no idea where to take shelter
"This situation is beyond comprehension," Bihar resident, Arshad Khaqani, told the BBC News website.
A report released by Unicef says there are fears of infectious diseases as hundreds of thousands of homeless crowd into relief camps.
The Kosi river flows from Nepal where it is called the Saptakoshi river. On 18 August a dam on the Saptakoshi burst, triggering the subsequent flooding in Bihar.
Officials in Nepal say hundreds of people there have been hit by illnesses such as diarrhoea and pneumonia and an estimated 50,000 are homeless.
They say nearly 1,000 houses have been completely destroyed. Power supplies and transport have been severely affected.
The costs to the economy are now estimated at one billion Nepalese rupees ($14.25m).
Meanwhile, in India's Uttar Pradesh state, which borders Bihar and Nepal, the health authorities say at least 400 people have died from water-borne diseases during the current monsoon season.
Officials say 181 of the deaths have occurred in the eastern districts from encephalitis carried by mosquitoes breeding on the water.
Have you been affected by the floods in Bihar? Send us your comments and experiences.
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