TALDYKORGAN: Thirty-seven people were killed Sunday when a fire ripped through a decrepit drugs treatment facility in the former Soviet republic of Kazakhstan, emergency officials said.

There was no information on what caused the fire, which began at roughly 5:30 am (2330 GMT Saturday) in Taldykorgan, a city in the southeast of the country close to Kazakhstan's main city of Almaty.

But officials said the blaze spread rapidly because of the age of the building and because firefighters were not informed quickly enough.

"Thirty-seven people have died," Kazakh Vice Prime Minister Serik Akhmedov, head of a commission investigating the fire, said at a hastily arranged press conference in Taldykorgan.

Earlier the emergency situations ministry said 38 people had died. There was no explanation for the discrepancy.

"The cause for the rapid spread of the fire was that the fire services received the announcement too late," Emergency Situations Minister Vladimir Bashko told reporters.

"Also, the building was very old, and because of the materials that had been used in construction the fire spread very quickly," he added.

At least 10 people were in hospital with fire-related injuries, two of whom had suffered severe burns and were in critical condition on Sunday evening, Bashko said.

Reporters were barred from visiting the scene of the fire or speaking with the injured.

It was unclear whether patients had been locked inside the building, as is common practice in such facilities.

Rescuers saved 40 patients and medical staff, the emergency ministry said, while firefighters took hours to extinguish the blaze, which spread out over an area of almost 650 square metres (7,000 square feet).

The fire quickly consumed the one-story building, which officials said was made of wood and had been built in 1951.

Kazakh Prime Minister Karim Masimov called for the creation of a commission to investigate the cause of the fire, putting his deputy Akhmedov in charge.

"The country's prime minister has entrusted the commission with carefully investigating the cause of this tragedy, and taking exhaustive measures to assist the victims," the government said in a statement.

Kazakhstan, an energy-rich Central Asian state that borders Russia and China, has struggled to maintain its aging Soviet-era infrastructure, despite having earned billions of dollars from its natural resources in recent years.

Deadly fires are common in the former Soviet Union, with retirement homes and other state-run facilities particularly prone to such accidents.

Earlier this year a fire at an ageing Soviet-era weapons depot in southern Kazakhstan triggered explosions that killed two and injured 16.

In 2006, 45 women were killed when a fire erupted at a drug treatment clinic in Moscow. The women had been trapped behind locked doors and barred windows during the inferno.