Twenty-three Russian conscripts were crushed to death when their military barracks collapsed in Siberia, the latest disaster blamed on apparent shoddy construction work and lax safety standards.

An entire section of military barracks, including parts of the roof and walls, collapsed on Sunday evening just outside the Siberian city of Omsk as paratroopers were resting, the defence ministry said.

"As a result of the collapse, more than 40 servicemen were injured," Investigative Committee spokesman Vladimir Markin said on Monday.

"Twenty-three conscripts died, the others were hospitalised with various injuries."

Nearly 20 injured men have been airlifted to top hospitals in Moscow, the defence ministry said.

The blue-and-white barracks -- built in 1975 and renovated in 2013 -- belonged to the Airborne Forces' 242nd training centre that prepares junior officers and armoured infantry vehicle drivers, among others.

President Vladimir Putin has been informed of the incident, which occurred in the village of Svetly just outside Omsk, some 2,200 kilometres (1,400 miles) east of Moscow, a Kremlin spokesman said.

"The president expressed condolences to the families of the victims of the accident at the Omsk training centre," the Kremlin said.

Putin was being regularly briefed by Defence Minister Sergei Shoigu, who has been tasked with providing all necessary assistance to the victims, the Kremlin added.

Survivor Maxim Kolmakov said his fellow servicemen realised that something was amiss when chunks of plaster began falling off.

"Everyone started running out of the barracks and the barracks began falling apart," he said in televised remarks, adding that some of the young men jumped from the second floor on to mattresses to save themselves.

In footage shown on national television, rescue workers formed a human chain to pass bricks and other debris to one another as they cleared the mountain of rubble from the collapse.

"Half of the heap has been cleared now," acting commander of Russian paratroopers Nikolai Ignatov said in televised remarks.

Nearly 350 rescue workers and search dogs have been dispatched to the scene, along with military prosecutors.

"Rescue works lasted through the night," a spokeswoman for the governor of the Omsk region told AFP. "The governor was there all night."

- 'As if army at war' -

Dozens of relatives of the injured or dead soldiers have already arrived in Omsk, the defence ministry said.

Authorities blamed the collapse on negligence by construction workers.

The Investigative Committee, which reports directly to Putin, opened a probe into negligence, violation of safety rules and abuse of power, adding that those found guilty would face up to 10 years in prison.

Markin, the committee's spokesman, said investigators were probing several explanations for the tragedy, including possible violations during renovations in 2013.

Regional prosecutors said a company behind the renovations had already committed violations during the construction of a residential building in the region of Tatarstan, adding they would look closely into its work.

The Omsk region will observe a day of mourning on Tuesday.

Building collapses and other infrastructure accidents are fairly frequent in Russia where the enforcement of safety regulations is lax and corruption rampant.

On Saturday a section of a residential building collapsed in the Urals city of Perm, killing two.

The latest tragedy represents a major blow to Putin who has made reviving the army after years of post-Soviet neglect a cornerstone of his policies.

The barracks has become the "paratroopers' mass grave," broadsheet daily Kommersant said.

"Honestly, it's as if our army were at war," wrote political commentator Anton Orekh.

"Soldiers die in Donbass, soldiers kill their fellow servicemen, soldiers die under the rubble of their barracks," he said, referring to eastern Ukraine.

Moscow deployed troops during the seizure of Crimea from Ukraine in March last year but suggestions regular forces are directly involved in the conflict in the east of the country have been denied by Moscow.