India's coast guard on Saturday launched an operation to trace about 400 fishermen who went missing during monsoon storms in West Bengal, officials said.
About 33 fishing boats went missing on Friday in the choppy waters of the Bay of Bengal in eastern India.
"Our team has been able to establish contact with some fishermen but we are yet to trace 25 trawlers," Iqbal Singh Chauhan, coast guard commander stationed in West Bengal, told AFP.
Naval vessels, hovercraft and helicopters have joined the rescue effort but incessant rainfall is hindering the search operation.
Chauhan said they had reports that more than 20 fishing boats had anchored at various isolated islands near the Sundarbans mangrove forest 120 kilometres south of Kolkata, capital of West Bengal.
"Preliminary reports suggest that most of the fishermen are safe but we are yet to establish direct contact with them," he said.
During storms in West Bengal, many captains find themselves unable to return to port and take refuge with their boats and crews along the coast.
Fishermen's Welfare Association chief Bijan Maity said five of the 33 trawlers had drifted to neighbouring Bangladesh and one had capsized, but there were no casualties.
Storms and cyclones which form over the Bay of Bengal every year kill hundreds and destroy cattle and crops in India's eastern states and in Bangladesh.
India has forecast a "normal" monsoon this year that could boost food production and ease high inflation. The strength of the annual June-September downpour is vital to hundreds of millions of farmers and to economic growth in Asia's third-largest economy which gets 80 percent of its annual rainfall during the monsoon season.