Emergency personnel work at the site of collapsed apartment building after a suspected gas blast in Magnitogorsk, Russia Image Credit: Reuters

Moscow – At least three people were killed and another 79 people were unaccounted for after a gas explosion rocked a residential building in Russia's Urals city of Magnitogorsk on Monday, a senior official said.

"Three people have been pulled alive from the rubble and three are dead," 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," he said, adding police were working to locate their whereabouts.

Rescue services in the Russian city of Magnitogorsk scrambled to find survivors after a suspected gas blast in the early hours of Monday caused the partial collapse of a high rise apartment building, killing at least two people, news agencies reported.

Media outlets in the city, located 1,700 km 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.

Citing the emergencies ministry, RIA news agency said 110 people lived in the building, and 48 apartments had been damaged.

The ministry said on its website that 16 people had been evacuated, and three had been rescued from the debris. It said the calamity could have been caused by a gas blast.

Reports said that the blast ripped through the building at around 0600 (0100 GMT) when many of the residents were asleep.

Monday is a public holiday before the New Year celebrations in Russia.