"Thirteen bodies were retrieved today (Monday). Although nobody yet knows the exact number of missing people, it is estimated that at least seven are still missing," state Special Relief Commissioner P.K. Mohapatra said.
Mohapatra earlier put the number of those missing at ten. The figure was revised on the basis of the latest information provided by the survivors.
More fire fighters and Odisha Disaster Rapid Action Force units joined the operation on Monday and the rescue and salvage process has since been intensified.
A six-member scuba diver team also joined the crew and they were trying to enter the sunken boat to find those missing.
The boat which went down in the Hirakud Dam reservoir, about 350 km from the state capital Bhubaneswar, around 4.30 p.m. Sunday, was carrying more than 100 people against a capacity of 70. Most of the passengers were picnickers.
The accident occurred when the people from Sambalpur and nearby areas were returning after a picnic on the other side of the reservoir.
Eyewitnesses said the mechanized boat capsized in the middle of the reservoir after water entered into it following a snag. The passengers tried hard to drain out the water from the boat, but in vain.
Many of the picnickers jumped off the boat in panic. They said the boat did not have basic safety measures.
Ordering an inquiry into the tragedy, Chief Minister Naveen Patnaik announced an ex-gratia of Rs.1.5 lakh to the next of kin of each of those dead. The Odisha government will also bear the cost of the treatment of the survivors.
He also deputed Odisha Finance Minister Prasanna Acharya and Revenue and Disaster Management Minister Surya Narayan Patro to the affected region to review the situation.
Congress vice president Rahul Gandhi, who is in the state on a two-day tour since Sunday, also took an aerial view of the tragedy site. Gandhi is scheduled to meet the survivors and hold discussions with the local officials.