More than 200 people have now been killed by Cyclone Aila which hit Bangladesh and the eastern Indian state of West Bengal, relief officials say.
They say that at least 500,000 people have been made homeless by the storm.
The situation is particularly grim in the Sundarbans, the mangrove forest and home of rare Bengal tigers, where thousands are stranded by flood waters.
Soldiers and border guards have joined relief efforts, but they are yet to reach some of the devastated areas.
Officials say the storm has weakened, but heavy rains continue to damage crops and cause floods and landslides in many areas.
Cyclone Aila made landfall in south-western Bangladesh on Monday afternoon. Coastal areas were flooded and uprooted trees caused chaos in Calcutta.
River banks and mud houses in Bangladesh and India have been completely destroyed and crops and fisheries have also been damaged.
Troops, border guards and policemen involved in relief and rescue operations have so far recovered 68 bodies from coastal districts of West Bengal, the BBC's Subir Bhaumik reports from Calcutta.
The Sundarbans delta - which straddles both the south-west of Bangladesh and the south-east of the Indian state of West Bengal - bore the brunt of the cyclone.
Officials say the situation there is "desperate".
District magistrate for South 24 Parganas Aoala Sen told the BBC that 27 bodies had been recovered from its villages so far.
"Our district is the worst affected," Ms Sen said.
Rains and landslides triggered by Aila have killed people all over West Bengal, including the north of the state and in and around Calcutta.
The cyclone has left more than 24,000 people homeless, with villages flooded with saline water, houses and boats destroyed, the Wildlife Protection Society of India (WPSI) says.
Many people are now huddled on embankments and on top of the few permanent constructions.
In Bangladesh, the death toll has risen to 127 after dozens of bodies were recovered on Tuesday.
The worst affected area was the Satkhira district where a local official said 31 bodies were found in one village.
Officials say nearly half a million people have been moved to temporary shelters.
Witnesses said many people were still stranded by the storm and faced shortages of food and drinking water.
Correspondents say that the fear in Bangladesh is that salt water from a tidal surge that followed the cyclone will contaminate non-saline surface water which is crucial for farming.