MOSCOW • At least three people were killed and a further 79 left unaccounted for after a gas explosion rocked a residential building in the Russian city of Magnitogorsk yesterday, a senior official said.

The explosion, which occurred in the early hours when many of the residents were asleep, led to a partial collapse of the high-rise apartment building, reports said.

Media outlets in the city, located 1,700km east of Moscow in the southern Urals, said it was unclear how many people were trapped in the debris but cries for help could be heard from beneath the rubble.

"Three people have been pulled alive from the rubble and three are dead," Mr Oleg Klimov, deputy governor of the Chelyabinsk region where the industrial city is located, was quoted as saying by state news agency RIA Novosti.

"The fate of 79 people is unclear," Mr Klimov said, adding that the police were working to locate their whereabouts.

RIA news agency said 110 people lived in the building and 48 apartments had been damaged. Yesterday was a public holiday in Russia.

REUTERS, AGENCE FRANCE-PRESSE