Indian authorities said on Wednesday that about 100,000 people were homeless after heavy rains this week caused flooding in the coastal districts of Andhra Pradesh state, with strong winds uprooting thousands of trees and electricity poles.
"Over 1000 people have been reported missing in the three coastal districts," state government official Praveen Prakash said.
Rescue workers in motorised rubber dinghies picked up people stranded in floods, while military helicopters dropped food and water packets to marooned people and lifted them off rooftops.
Thousands were evacuated to relief camps.
Most of the 50 killed in India were electrocuted or died in house collapses, officials said.
In Bangladesh, leaders of the low-lying nation's fishing community said on Wednesday that they had not heard from about 300 fishermen after the storm triggered high waves and heavy rain along the coast this week.
"We are expecting some of them to come back," Kabir Ahmed Sawdagar said from the coastal city of Cox's Bazar, adding that in the past fishermen reported missing had returned safely weeks after a storm.
"Over 1000 people have been reported missing in the three coastal districts"
Indian state government official
But Golam Mustafa Chowdhury, president of the Fishing Trawlers Association in the coastal district of Barguna, said that 31 trawlers with about 450 fishermen sank during the storm and he feared most of the men on them had drowned.
Other fishing groups said some missing fishermen had returned and others may have been pushed towards Indian waters.
On Wednesday, there was no electricity in about 100 towns and 1300 villages on Andhra Pradesh's coast where rail, air and road traffic has been severely disrupted.
Hundreds of vehicles were stranded on a key highway linking eastern India with the south of the country and the airport in the port city of Visakhapatnam was closed for the second day as its runway was partly waterlogged.
Rail, air and road traffic in Andhra
Pradesh was severely disrupted
Rains had eased in most parts of the state on Wednesday, but its largest river, the Godavari, had burst its bank in several areas.
Storms and cyclones that form in the Bay of Bengal in September and October slam into India's eastern coast and neighbouring Bangladesh almost every year.
In 1977, about 10,000 people were killed when a cyclone lashed Andhra Pradesh. Nineteen years later, about 2000 people were killed in another cyclone.