Rail services to the Northeast from rest of the country halted till Wednesday.
The floods in Assam on Monday claimed three more lives, taking the total deaths count to 102, and hit nearly 32 lakh people in 25 districts, besides snapping rail connectivity to the Northeast.
Two persons died in Morigaon and one in Golaghat during the day.
With the three deaths, the deaths in the second wave of floods in the state has gone up to 18, while the figure for this year's flood related incidents climbed to 102, including eight in Guwahati, Assam State Disaster Management Authority (ASDMA) report said on Monday.
A total 3,192 villages are under water and 1.79 lakh hectares of crop area have been damaged, it said.
ASDMA said 31.59 lakh people are affected in Dhemaji, Lakhimpur, Biswanath, Sonitpur, Udalguri, Darrang, Baksa, Nalbari, Barpeta, Bongaigaon, Chirang, Kokrajhar, Dhubri, South Salmara, Goalpara, Morigaon, Nagaon, Karbi Anglong, Golaghat, Jorhat, Majuli, Sivasagar, Dibrugarh, Tinsukia and Kamrup districts.
The train services to the Northeast from the rest of the country have been stopped till Wednesday in view of the flood in Assam, West Bengal and Bihar.
"The Railway Board has decided to cancel all incoming trains from various parts of the country towards NE Region, which were to reach either Katihar or Malda town till 10 am of August 16, 2017," Northeast Frontier Railway chief public relations officer (CPRO) Pranav Jyoti Sharma said in a statement.
"Heavy rainfall in the last 72 hours in West Bengal, Bihar, Assam and other NE states has resulted in railway operations being severely hampered as rain water has affected railway tracks at several places in Katihar and Alipurduar Division of NF Railway," Mr Sharma said.
In view of the flood situation, 11 outgoing trains have been cancelled by NF Railway today, Mr Sharma said, adding four other trains have been short-terminated at various locations.
Yesterday, 22 trains were cancelled, while 14 others were stopped at various places as tracks were flooded.
Until Sunday, over 22.5 lakh people were hit by the latest wave of flood across 21 districts in Assam.
As per the report, Dhubri was the worst affected district where 7.79 lakh people have been hit by the deluge, followed by Morigaon (3.83 lakh people).
Authorities are running 556 relief camps and distribution centres in 21 districts, where 2,06,467 people are taking shelter at present.
At least 2,000 persons have been evacuated to safer places by the Army, the SDRF and the NDRF personnel in many districts.
The flood has damaged embankments, roads, bridges and other infrastructures in Dhemaji, Sonitpur, Darrang, Nalbari, Barpeta, Bongaigaon, Morigaon, Nagaon, Golaghat, Biswanath, Chirang, Kokrajhar, Dhubri, South Salmara, Majuli, Dibrugarh, Udalguri and Sivasagar.
Heavy erosion have been witnessed in Dima Hasaon district, it said.
Currently, Brahmaputra is flowing above the danger mark at Guwahati, Nimatighat in Jorhat, Tezpur in Sonitpur, Goalpara and Dhubri towns.
Other rivers like Burhidehing at Khowang in Dibrugarh, Dhansiri at Numaligarh in Golaghat, Jia Bharali at NT Road Crossing in Sonitpur, Puthimari at NH Road Crossing in Kamrup, Beki at Road Bridge in Barpeta, Sankosh at Golokganj in Dhubri, Katakhal at Matizuri in Hailakandi and Kushiyara at Karimganj town are flowing above the danger marks.
Most of the forest areas in Kaziranga National Park, Pobitora Wildlife Sanctuary and Lawkhua wildlife sanctuary are under the flood waters.
Meanwhile, speaking to Assam Chief Minister Sarbananda Sonowal for the second consecutive day, Prime Minister Narendra Modi expressed his concern at the critical situation and asked about the relief measures and rescue operations.
Mr Sonowal also spoke over phone with Bihar Deputy Chief Minister Sushil Kumar Modi and urged him to extend all cooperation in ensuring the safety and other essential requirements to passengers stuck at Kishanganj station after termination of trains due to floods.
In view of the critical flood situation in the state, Mr Sonowal directed to cancel the traditional High Tea programme as part of the celebrations of 71st Independence Day.