Russian authorities faced growing anger on Tuesday over the sinking of an aging, overcrowded tourist boat in the Volga River after divers found the bodies of dozens of children in the wreckage.

Eighty-eight people, including 16 children, were confirmed dead but the toll could reach 129 in a disaster that has underlined concerns about negligence and corruption in Russia and prompted suggestions it could have been avoided.

Prosecutors said the Bulgaria riverboat had no license to carry passengers and had engine problems when it left port. Officials said it was meant for up to 140 people but had been carrying 208, including 25 unregistered passengers.

President Dmitry Medvedev promised harsh punishment for anyone who violates transport safety rules and said tougher legislation was needed. Prime Minister Vladimir Putin called it "an enormous misfortune."

"It's completely obvious that we cannot tolerate this any more," Medvedev told legislators.

He and Putin will hope to shift any blame away from the state before a parliamentary election in December and a presidential election in March. They have not said which of them will run in the presidential vote.

But patience appeared to be wearing thin. "After every such accident the actions of the authorities are exactly the same," popular web-portal Gazeta.ru wrote in an editorial.

"The degree of irresponsibility at all levels of authority and among citizens has reached the level of being a threat to Russian national security every day."

The Bulgaria sank within minutes about three km (two miles) from shore during a cruise on Sunday after listing onto its right side in a thunderstorm. Authorities said 79 of the 208 people on board had been rescued.

One of the survivors, whose daughter was killed, said the boat, built in 1955, had swiftly turned into a "metal coffin" after it got into difficulty.

DAY OF MOURNING

A national day of mourning was called on Tuesday. Church ceremonies were held across Russia and flags flew at half mast.

Hundreds of mourners gathered at a pier in the nearby city of Kazan to throw red carnations into the Volga. Passing ships blasted horns in solidarity for the dead and the embankment was covered in fluffy toys and tea candles in plastic cups.

"The ones who let this boat go out to water are guilty," said Albina, a Kazan resident, wiping back tears as Mozart's "Requiem" was played.

Emergencies Ministry officials said divers saw the bodies of children bodies in the wreckage when they came to a recreation area in the sunken boat. Survivors said about 30 children had gathered there shortly before the boat went down.

Most survivors were picked up by a passing riverboat after two commercial vessels went by without offering help.

"They were climbing aboard our ship, all black and covered in fuel oil, crying hysterically. I can still see it," said Svetlana Alexeyeva, who was on the ship that rescued them.

Prosecutors opened a criminal investigation and detained the head of the company that leased the boat, Agrorechtur, and a river transport inspector, Itar-Tass news agency said.

Russia's deadliest river disaster since 1983 did not surprise many Russians, inured to fatal accidents.

Many disasters are blamed on negligence and corruption despite tough talk from Medvedev and Putin, who as president promised to bring order with a "dictatorship of law."

Alexander Lebedev, the Russian owner of British newspapers The Independent and The Evening Standard, said rampant corruption at the official level and crumbling Soviet-era infrastructure were to blame for such tragedies.

"Why do we have so many disasters? It is a systematic failure of the system," he told Reuters in an interview.