The death toll from floods sweeping South Asia has climbed above 1,000, officials said Thursday, as rescue teams try to reach millions stranded by the region's worst monsoon disaster in recent years.

Thousands of soldiers and emergency personnel have been deployed across India, Bangladesh and Nepal, where authorities say a total of 1,009 bodies have been recovered since August 10 when intense rainfall started falling.

Twenty-six bodies were found Wednesday in Bihar, a hard-hit state in India's east, taking the death toll there to 367, said Anirudh Kumar, a top state disaster management official.

"We still have nearly 11 million people affected in 19 districts of the state," he told AFP, adding 450,000 flood evacuees had taken shelter in government refuges.

In neighbouring Uttar Pradesh, floods have swamped nearly half the vast state of 220 million, India's most populous.

Disaster management agency spokesman T P Gupta told AFP said 82 people had died and more than two million affected by the disaster there.

The state borders Nepal, where 146 people have died and 80,000 homes destroyed in what the United Nations is calling the worst flooding in 15 years.

Nepal's home ministry warned the death toll could rise as relief teams reach more remote parts of the impoverished mountainous country.

In the Himalaya region in India's northwest, landslides caused by heavy rain have claimed 54 lives, the vast majority in one huge avalanche of mud that swept two buses off a mountainside.

The situation was slowly easing in West Bengal and Assam, two states in India's east and northeast where 223 people have died.

Floods in Assam -- the second wave to hit the state in less than four months -- have wrought widespread destruction, killing 71 people and swathes of native wildlife, including a Bengal tiger and 15 rare one-horned rhinos.

In the low-lying state of West Bengal, where 152 people have died, hundreds of thousands have escaped submerged villages by boats and makeshift rafts to reach government aid stations.

Across the border in Bangladesh, water levels were slowly returning to normal in the main Brahmaputra and Ganges rivers.

The government's disaster response body said Thursday the death toll stood at 137, with more than 7.5 million affected since flooding hit the riverine nation.

Nearly 350 people died in the first wave of floods that began in mid-July in India's western states of Gujarat and Rajasthan, and several remote northeastern states.