PATNA (India) - AUTHORITIES warned villagers in flood-ravaged northern India on Friday not to return to their homes because an unpredictable river that burst its banks could overflow again.

But thousands ignored the warning and took the receding waters as a sign that the danger had passed, officials said.

An area that is home to about 1.2 million people has been flooded for more than two weeks after monsoon rains caused the Kosi River in neighboring Nepal to burst its banks and turn hundreds of square miles (hundreds of square metres) of India's impoverished Bihar state into a giant lake.

The river levels have declined by up to two feet (less than 1 metre) over the last three days, leading thousands of people who had fled their villages in search of higher ground to begin a journey home, said Brig. P.F. Rathi, an army official leading the rescue operation.

Officials strongly urged them to head for the 250 relief camps and keep away from the hardest-hit districts. Helicopters air-dropped pamphlets warning people of the danger of fresh floods, and the state's chief minister took to the radio to spread the message.

'People are under the false notion that the river has receded, but the fact is that it can swell any day due to the unpredictable nature of the river and the final round of monsoon rains due later this month,' said Mr Rathi.

Officials could not say how many people were heading back to the affected areas but they dispatched rescue workers and troops to stem the return.

Anant Kumar Bhagat was going back to his native Kumarkhand village in hopes of reuniting with his brothers and his parents, who he hasn't seen since the area flooded August 21.

'The waters have gone down so I think they will also try to reach the village,' Mr Bhagat said.

Meanwhile, the government pressed on with its relief efforts and tried to reach more than 100,000 people still stranded in the flooded areas, said Mr Nitish Mishra, the state disaster management minister. But with the river levels falling, it was becoming harder to convince villagers to leave.

Mr Rathi said he sent seven army boats to a flooded village in Supal district to rescue 250 people on Friday, but the boats returned with only five villagers on board.

'We kept pleading but they simply ignored our request,' Mr Rathi said. Rescuers have already moved more than 780,000 people from roughly 900 villages, he said.

Authorities have only confirmed 38 deaths, but it is widely believed the final toll will be significantly higher.

Disaster officials did not say when it would be safe for villagers to return, but they have cautioned that many areas will likely remain flooded until monsoon rains taper off in November.

That means refugees could be stuck in camps for several months.

The monsoon season, which starts in June, brings rain vital for the farmers of South Asia but also can cause massive destruction. -- AP