The death toll in the Andhra Pradesh boat capsize rose to 21 as one woman died during treatment at a private hospital in Amaravati on Monday, Krisha District Collector B Lakshmi Kantam said.
The mother of one of the deceased women died of shock when the body was taken to their residence in Ongole on Monday, a senior police official said.
The boat, carrying 42 people and three crew members, capsized in the Krishna river near Vijayawada on Sunday.
While 21 people were rescued, search teams fished out 20 bodies.
Four people, including two crew members, were still missing, and a massive search operation involving National Disaster Response Force and state teams was on.
Among the deceased were 10 women and a teenage boy, the collector said.
Andhra Pradesh Chief Minister N Chandrababu Naidu conducted an aerial survey of the river stretch between Bhavani Island and Pavitra Sangamam, and visited the accident spot at Ferry village.
On Monday morning, he also visited the Andhra Hospital at Gollapudi where four of the 21 people rescued on Sunday were undergoing treatment.
Of the rescued, 17 were discharged after first-aid.
Bhulaxmi, 57, died of cardiac arrest at the Andhra Hospital on Monday evening. The body of her husband Sudhakar was fished out on Sunday. A total of three couples died in the tragedy.
One of the couples, Pasupuleti Seetaramaiah and Anjamma, was related to state Director General of Police (in-charge) Nanduri Sambasiva Rao.
Communist Party of India national secretary K Narayana lost three of his close relatives in the mishap.
Lakshmikantam of Ongole died of shock after she saw the body of her deceased daughter Leelavati, the police official said. A widow, Leelavati was among those killed in the boat tragedy and her body was taken home on Monday afternoon after post-mortem.
While 16 bodies of the deceased were fished out of the river on Sunday night, four more were retrieved on Monday morning.
"With deep regret and pain", the chief minister shared these details in a statement made in the legislative assembly on Monday.
He said the boat was operated illegally by River Boating and Adventures Private Limited and a case has been registered against five people under Section 304 (2) of the Indian Penal Code -- causing death by rash or negligent act not amounting to culpable homicide.
"The driver and the helper of the boat are still missing, while body of the assistant driver has been recovered this (Monday) morning. We will take stern action and punish the guilty as per law," he said.
Those victims covered under the Pradhan Mantri Jeevan Jyoti Beema Yojana would be extended Rs 10 lakh compensation per family, while those uncovered would be paid Rs 8 lakh.
A two-member committee comprising an Indian Administrative Services and an Indian Police Service officers would thoroughly probe the incident and suggest safety and precautionary measures to prevent such tragedies in future, the chief minister said.
"It is due to the greed of the private operator that this tragedy occurred. They did not have any permission (to operate the ferry service). The driver was not experienced and had no knowledge of the (river) route. They behaved so irresponsibly and caused the mishap," said Naidu.
He complimented two fishermen of Ferry village -- Nadakuditi Pitchaiah and Kanna Sivaiah -- for displaying exemplary courage and rescuing several passengers of the ill-fated boat.
He also commended the National Disaster Response Force, State Disaster Response Force and other government teams that took part in the search and rescue operation.
The Assembly passed a resolution mourning the tragedy.