New Delhi - The Indian army Thursday said there was an acute shortage of tents to house hundreds of thousands of flood victims in the eastern state of Bihar, news reports said.

The army, tasked with relief and rescue operations, has been able to send only 500 tents adequate for accommodating 5,000 people, the IANS news agency reported.

This was due to a shortage resulting from sending 1,750 tents to earthquake-hit China in May.

The number of tents was inadequate, with some 3.5 million people being affected or displaced by floods triggered after the monsoon-driven Kosi river changed course.

"The army has been able to send only 500 tents so far due to the shortage subsequent to the tents sent by India to China after the earthquake. Moreover the army needs to maintain its reserves well," an army official told IANS requesting anonymity.

Army sources said they would be able to manufacture an adequate number of tents in the next three months.

"It is difficult to estimate ... but thousands of the flood-victims have been without a roof over their heads either in the affected areas or the relief camps," said Sudhir Meen, an official at the state flood control centre.

"Since several areas will remain flooded till monsoon rains taper off by the next month, it is a big challenge to provide tents and rehabilitate the evacuated people," he added.

An estimated 680,000 people have been evacuated and of them 256,000 have taken shelter at 285 relief camps, the state's top disaster management official, Pratyay Amrit, said.

Meanwhile, more than 4,500 army and navy personnel were evacuating thousands of people from six critical and remote areas in flood-hit Supaul and Madhepura.

"We should complete evacuation of 250,000 people over the next four to five days," Amrit said. The official said 11 military helicopters have dropped 69,000 food packets to the stranded villagers since Wednesday.

Authorities have also rushed 180 medical teams comprising more than 1,000 doctors amid fears that crowded and unsanitary conditions could lead to outbreaks of cholera and diarrhoea.

Although the officials have confirmed 66 deaths, aid agencies such as ActionAid estimate that more than 2,000 could be missing or dead in the final toll after the floodwaters recede.

Officials in the state flood control centre admitted that these were among the worst floods to hit the region. The floods were more severe last year, claiming nearly 900 lives and affecting 20.5 million people in 10,000 villages.

India's north-eastern state of Assam has also been hit by floods as 16 of its 27 districts were inundated with the Brahmaputra River overflowing its banks.

Nearly 1 million people were displaced and 15 were dead in the second wave of floods since June as the army carried out operations in the state.

A total of 1,785 people have died this year across in 20 of India's 29 states in floods brought on by the annual monsoon rains that last from June to September.

More than 840 fatalities were reported from the northern state of Uttar Pradesh alone, said officials at India's federal Home Ministry. (dpa)