A Dornier aircraft with diving teams has been sent to Rajahmundry, Andhra Pradesh, where a boat carrying about 40 people capsized in Godavari river on Tuesday.
Additional diving teams have also been sent by two helicopters to join the rescue operations, Eastern Naval Command, which is leading the rescue efforts, said.
Till now, 17 people have been rescued while others are still missing.
According to police, the boat sailed from Devipatnam to reach Kondamodalu at 3.30 pm on Tuesday. When the boat was 10 minutes away from the banks, heavy rain and high-velocity winds started during which the small vessel lost its balance and capsized.
Prime Minister Narendra Modi has expressed his anguish over the incident on Twitter.
"Anguished by the capsizing of a boat in Andhra Pradesh's East Godavari district. Condolences to the bereaved families. I pray for the safety of those missing," he tweeted.
Andhra Pradesh Chief Minister N. Chandrababu Naidu also took to the micro-blogging site and said the incident is "highly painful" and officials have been asked to take up the rescue operations on a war footing.