Moscow (AFP) - Twenty six people died and nearly a thousand sought medical treatment after wildfires blamed on reckless human behaviour swept through Siberia, Russian authorities said on Monday.

Some 5,000 rescue workers battled through the night to contain the blazes in the Khakassia region of southeastern Siberia, where 23 people died, said investigators.

Fires also raged in eastern Siberia, claiming three lives including that of a three-year-old girl, authorities in the Chita region told AFP.

The Kremlin said President Vladimir Putin was personally coordinating the emergency response.

The authorities blamed the fire on human carelessness, with people suspected of setting dry grass alight and strong winds and warm temperatures then causing the fire to spread.

"This fire would not have happened if no one played with matches," said deputy emergencies minister Alexander Chupriyan, referring to the inferno that ripped through Khakassia on Sunday, where temperatures hit 25 degrees Celsius.

"And it was adults and not children who did this."

State television said the fires were so intense they could be seen from space, on satellite images, and that the flames reached about three meters in some places.

A senior medical official, Natalya Kogan, told reporters that more than 900 people sought medical help in Khakassia.

A total of 77 people were hospitalised, a spokeswoman for regional authorities, Irina Emelianova, told AFP earlier in the day.

Eight of those hospitalised were in critical condition.

"We have never had this before," Emelianova said, referring to the scale of the disaster.

More than 30 villages have been affected, she added. Some 5,000 people had been left homeless, including 1,000 children.

Regional authorities reported large livestock losses as a result of the blaze.

At least 700 cattle and some 3,000 sheep had perished, they said in a statement, expressing concern that surviving cattle had no grass to graze. "Tens of square kilometres of land have been burned," they added in a statement.

Moscow-based investigators have opened five criminal probes into the Khakassia fires.

On Tuesday, the region will observe a day of mourning.

- Deaths in eastern Siberia -

Rescue workers in eastern Siberia also raced Monday to put out wildfires in the Chita region.

Three people died as a result of the fires, including a three-year girl and a woman who died of a heart attack, a spokeswoman for local authorities, Elena Fyodorova, told AFP.

Thirteen people sought medical help, one of whom was hospitalised, she added.

Regional Governor Konstantin Ilkovsky called on locals not to burn grass and urged residents of several settlements to evacuate.

"The situation is very serious," he was quoted by his administration as saying.

Authorities said they were also battling fires near local ammunition depots but insisted there was no danger of explosions.

Russian farmers often set fire to dry grass to regenerate fields after the winter, sometimes accidentally sparking massive blazes that result in deaths and damage to homes.

In 2010, during Russia's worst heatwave in decades, smoke from wildfires and burning peat bogs in the centre of the country choked Moscow for several days.

Officials said the death rate in the Russian capital soared by 50 percent over the period.