Sources in the Disaster Management Authority (SDMA) said a total of 1,604 villages had come under water.
The government has opened 169 relief camps for the marooned, the sources said, adding that close to 1.50 lakh people were staying in these camps.
SDMA sources confirmed that four people had died due to floods -- one in Dibrugarh and three in Tinsukia districts.
Unofficial sources, however, put the death toll at eight.
The sources said the figures might increase as many people were reported missing.
The Brahmaputra and some of its tributaries are flowing above the danger level and maintaining a rising trend.
A red alert has been sounded in Majuli Island. All educational institutions have been closed indefinitely from Tuesday due to the rise of water level.
The Indian Air Force, Army, National Disaster Response Force (NDRF) and the State Disaster Response Force (SDRF) are engaged in relief and rescue works.
Around 8,000 people had been rescued till Sunday evening in Tinsukia, Sonitpur and Dhemaji districts.
Air Force helicopters dropped 250 quintal of food items among the marooned at Sootea in Sonitput district and at Sadia in Tinsukia district till late Sunday.
The flood waters have damaged crops and fishery industries in various places.
A large portion of the the Dibru-Saikhowa National park, the Kaziranga National Park and the Pobitara Wildlife Sanctuary have got submerged, the sources said.
Guwahati: The flood situation remained grim in Assam on Monday, with more and more areas submerged every day across 16 districts, marooning some 10 lakh people, officials said.
First Published: Monday, September 24, 2012, 15:42