Incessant rains in the past 48 hours has sent the entire northeast reeling with floods, landslides, and disruption in road and rail communication affecting more than one crore people across the region even as Prime Minister Manmohan Singh arrives later this afternoon to survey the devastation.

At least 102 people have died in the current wave of floods and rains across the region.

The water level of the Brahmaputra and Barak and their tributaries, which started receding in the past few days, crossed the danger level again at several places because of continuous rains in the past 48 hours.

Dr Manmohan Singh will arrive Guwahati's Borjhar airport and straightaway undertake an aerial survey of Assam's flood-hit areas along with Assam Governor Ajai Singh and Chief Minister Tarun Gogoi. Later, he would hold a review meeting at the airport itself. After addressing a press conference, the prime minister will fly back to Delhi.

Road communication between Assam capital Guwahati and the oil and tea rich eastern Assam districts of Dibrugarh, Tinsukia, Sibsagar and Jorhat has been disrupted with surging waters of the Brahmaputra overtopping the vital National Highway 37 at several places in Nagaon district.

States like Tripura, Manipur and Mizoram have been completely cut off for the past three days with landslides at many places bringing  traffic to a halt.

On the world's largest riverine island of Majuli, internal communication has been totally disrupted. The flood situation in several other upper Assam towns was also aggravated following heavy rainfall in Pasighat in Arunachal Pradesh today.

Sources in the Central Water Commission said Pasighat recorded 421.3 mm of rain, the highest this year. Stranded people of seven villages near Kamalabari were evacuated. The marooned villagers have been shifted to highlands along the embankment.

Official sources said 70,000 hectares of land and one lakh people in 100 villages on the island have been affected by the floodwaters of the Luit and Subansiri, the two tributaries of the Brahmaputra. Erosion has also devastated vast areas of the island.

The Brahmaputra is flowing 2.08 metres above the danger level in the area. This is the third occasion in the past 16 years that the Brahmaputra's water level has crossed the 2-metre mark. In 1988, the water level rose to 2.23 metres and in 1991, to 2.33 metres.

The river has also started flowing above the danger mark again at several places in Lower Assam, including Guwahati.

In south Assam districts, the situation took a turn for the worse as all the major rivers, including the Barak, whose water level had been falling in the past week, registered a fresh rise above the red marks in the wake of the incessant rains during the past 36 hours.

The Barak has now been flowing half-a-metre above its danger mark clogging arterial roads, inundating the huge tracts of farmlands and uprooting fresh batches of people from their homes in Cachar and Karimganj districts.