The devastating floods that claimed at least 171 lives two months into President Vladimir Putin's third Kremlin term is expected to draw new attention to his handling of man-made and natural disasters.

Putin's 12-year reign of Russia as prime minister, president, prime minister and now president again has been dogged by major disasters such as the sinking of the Kursk submarine and several plane crashes.

Critics have repeatedly criticised him for the often slow response to crises and an inability to overhaul the country's Soviet-era infrastructure.

The first large-scale tragedy since Putin's return to the Kremlin in May has underlined the people's deepening distrust of the authorities and is expected to fuel the nascent protest movement against the strongman's rule, experts said.

The disaster is "not good news" for Putin as Russians are no longer willing to trust officials, said Olga Kryshtanovskaya, a sociologist who was until recently an active member of the ruling United Russia party.

"There is a problem of distrust," Kryshtanovskaya told AFP. "This distrust has grown rapidly since the Duma elections in December. The regime is in a situation where it cannot function as before."

The announcement of Putin's return to the Kremlin and fraud-tainted parliamentary polls last December triggered unprecedented protests against the leader.

Protesters blamed him for building a rigid system that enriches his inner circle at the expense of ordinary Russians.

"Pressure on the authorities will be especially strong in moments like this," Kryshtanovskaya said, noting that opposition leaders have been the first to announce a call for donations to the floods victims.

"Why did Krymsk sink?" opposition Novaya Gazeta newspaper headlined its story on its website Sunday.

It was a thinly-veiled reference to Russia's bungled rescue operation of the Kursk submarine that sank in 2000 with 118 people onboard.

"It sank," Putin said memorably when asked about the first major disaster of his first presidential career by Larry King on CNN.

Recent tragedies on Putin's watch include last year's sinking of the Bulgaria pleasure boat, in which more than a hundred people died; a plane crash last September that killed 44 people, including a popular hockey team; and the capsizing last December of an oil rig in the icy Okhotsk Sea waters, with dozens missing and presumed dead.

In this latest disaster, Putin has sought to project an image of a leader in control, personally inspecting the damage and telling local officials that Russia's top investigator would conduct a probe to see "who acted how."

But many victims in Krymsk said they were unimpressed as they complained of being left to their own devices in mud-filled houses without drinking water.

Their anger has been stoked by speculation that the sluice gates of a nearby water reservoir were opened overnight, flooding the town.

The rumours persisted even after Putin was told by officials on state television that this was not technically possible.

Investigators opened a criminal investigation into possible negligence but did not provide further details.

"Why are we always flooded!" an angry crowd yelled at Alexander Tkachev, the governor of Krasnodar region, in televised footage on Sunday as he struggled to pacify the victims.

"You think we had to go door to door?" the governor, an ally of Putin and one of longest-serving regional leaders, asked defiantly after locals complained there was no flood warning.

"And would you just pack up and leave?" he asked.

Local authorities have amassed a large amount of provisions in Krymsk, but there was no system of distribution, and elderly people remained without food, Krasnodar environmental activist Suren Gazaryan told AFP after spending two days in the town with a group of volunteers.

"A mechanism that would ensure personal safety of the people has not been created in the country," said Lilia Shevtsova, a political analyst at Moscow Carnegie Center.

"There exists a complete disregard for the life of an ordinary Russian," she said, adding the country has to deal with large-scale natural and man-made disasters every year.

"The problem is in the very model of the state," she said. "This delegitimises the authorities."