A government spokesperson said floodwaters of Drupang and Sessa rivers, both tributaries of the Brahmaputra river, entered at least 40 villages and forced residents to take shelter on higher ground and railway tracks.
“There has been a breach of about 20 to 30 metres in two embankments and that led to floodwaters entering settlements,” a district official said.
“One person drowned while trying to escape the surging floodwaters,” he added.
Measures are being taken to plug the breaches in the mud embankments.
"We have sounded maximum alert and have already kept disaster management teams on standby. We are also taking stock of essentials and other commodities in the district," the official added.
The 2,906-km-long Brahmaputra is one of Asia's largest rivers and traverses its first stretch of 1,625 km in China's Tibet region, the next 918 km in India and the remaining 363 km through neighbouring Bangladesh before flowing into the Bay of Bengal.