At least four people died Monday when sections of an apartment building collapsed after an apparent gas explosion in Russia's Ural Mountains region, officials said.
The authorities said five others were hospitalized with injuries, and 68 other residents remained unaccounted for in the accident in Magnitogorsk, a city of 400,000 about 1,400 kilometers (870 miles) southeast of Moscow.
The nation's top investigative agency, the Investigative Committee, said the collapse of a section of the ten-story building was apparently caused by a gas leak. It happened before dawn when most residents were still asleep on the New Year's Eve.
Nearly 1,400 rescuers were searching for those who could have been buried under debris.
Emergency workers have evacuated residents of nearby sections of the building, fearing they could also tumble down.
The Kremlin said that President Vladimir Putin has been briefed on the situation. Cabinet officials arrived in Magnitogorsk to oversee the rescue efforts.
Gas explosions in Russian homes and businesses are common, and they are usually blamed on neglect of safety rules or poor maintenance.