Flood victims fought off hungry animals and battled waterborne diseases in South Asia on Thursday as unrelenting monsoon rains caused fresh flooding in the region, already battered by weeks of bad weather.

The death toll in eastern India alone rose by over 100 in the past week with thousands more marooned or made homeless as bloated rivers burst mud embankments.

Authorities across South Asia -- where around 850 people have drowned, been crushed by landslides or died from snakebite and waterborne infections since mid-July -- said they were struggling to help millions of victims.

For some in the impoverished Indian state of Bihar, it is a struggle for survival as jackals and monkeys have attacked dozens of villagers over the past few days.

"Wild animals like jackals and monkeys are biting our wives and children and snatching bread from their hands," said Lalan Raut from the flood-hit Madhubani district.

"They are on a looting spree and are killing our goats and small rabbits."

Residents said the wild animals faced a shortage of prey since huge areas of the state were under water.

Doctors said they had reports of at least 60 cases of animals attacking villagers.

"We are rushing anti-rabies vaccines to every district," said Biltu Paswan, a senior government doctor.

All schools and colleges were shut in the capital Patna as flood waters swamped low-lying areas and entered buildings.

Many in the densely populated state of 90 million have complained of poor aid efforts. On Thursday, villagers demanding more food clashed with police in some places, officials said.

Workers Missing

In the neighbouring state of West Bengal, heavy rains flooded villages in three districts this week, forcing more than 25,000 people out of their homes.

A bridge collapsed in the state's Birbhum district, and many trains were cancelled or diverted across the region.

A weather official said more rains were forecast for eastern India because of a storm over West Bengal.

Further north, in the Himalayan state of Himachal Pradesh, around 60 people are believed to have died after a cloudburst caused a landslide that buried an entire village on Tuesday.

Many victims were labourers working on hydro-electric power projects.

"We have so far managed to recover only five bodies and the rest of the dead are buried under several feet of heavy debris consisting of huge boulders," said Tarun Kapoor, a senior police officer.

In neighbouring Bangladesh, the toll from floods rose to 516 with 35 fatalities reported overnight, the health ministry said.

More than half the low-lying and riverine nation has been affected by the flooding, and officials said typhoid, hepatitis and diarrhoea had broken out in most flood-hit areas.

So far, more than 50,000 people have been treated for diarrhoea and dysentery, they added.

"Not only contamination, but waterlogging and cross-leakage of water supply and sewerage lines are also responsible for the outbreak," said Habiba Khatun of the government's health directorate.

Each year, monsoon rains cause death and destruction in South Asia but the annual downpours are also vital for the region's agricultural production and overall economic growth.