A government spokesperson said up to 250 villages in four districts have been hit by the floods so far - Lakhimpur, Dhemaji, Jorhat and Tinsukia.
Two youths drowned late on Friday in the Dibru river, a tributary of the Brahmaputra in Tinsukia district in eastern Assam, when they went in a country boat to collect timber floating in the river.
A vast stretch of the Dibru Saikkhowa National Park in Tinsukia has come under water with forest guards forced to move out of the sanctuary, besides the wildlife scampering for safety. "We don't know if thefloods have swept away smaller animals like deer. We are unable to go inside the park due to rising water," a park official said.
An estimated 100,000 people are now displaced in the worst-hit Lakhimpur district alone, about 400 km east of Assam's main city Guwahati.
"Most of the flood-hit people are now taking shelter in raised platforms, on railway tracks, and also in government schools and offices so far untouched by thefloods," the official said.
A Central Water Commission bulletin said the Brahmaputra and its tributaries were flowing above the danger mark in at least eight places.
Gushing floodwaters had breached at least four vital mud embankments in the state.
South Asia's largest river island of Majuli in Jorhat district has also been hit by the floods with a breach in a mud embankment reported Thursday night, leaving thousands of people stranded on raised platforms.
Over 50 villages in Dhemaji district have also come under water.
This is the second wave of floods in Assam this year - the first wave hitting the same district last month although the magnitude was not devastating.
Meanwhile, a massive thunderstorm lashed parts of Sonitpur and Lakhimpur districts late Thursday, damaging nearly 100 houses.
"Two policemen on duty were injured when the roof of a roadside house they were taking shelter in collapsed in the heavy thunderstorm," a police official said.
