Road communication to Arunachal Pradesh through Lakhimpur and Dhemaji has also been disrupted following deteriorating flood situation caused by incessant rainfall, they said.
The flood-prone Dhemaji district was cut off from the rest of the country with the rising water of Jiadhol river breaching two embankments and submerging National Highway-5.
In neighbouring Lakhimpur district, the situation remained critical with more than 50 villages affected and flood water inundating roads and bridges in various places.
The Brahmaputra and its tributary Dihing, which were flowing above the danger level, have flooded 10 villages in Dibrugarh district, they said.
The situation in Tinsukia, where two boatmen had drowned yesterday, was also critical.