Russia gas explosion 2018 dec
© Screenshot / Ruptly
At least four people have been killed and four others injured, while the fate of 68 remains unknown after a gas explosion shattered a 10-story residential building in downtown Magnitogorsk in Russia's Urals.

The blast rocked the apartment complex on Monday at around 6am local time, completely collapsing one of its sections, videos from the scene show.

The disaster left at least four people dead, according to local officials. Two adults and two children were rescued from the rubble and hospitalized with their injuries.

There were 111 residents registered as living in the apartment complex. The fate of 35 remains unclear, the Emergencies Ministry told reporters.

The tragedy was caused by a gas explosion, the regional office of the Federal Security Service (FSB) confirmed.

A woman living on the fourth floor of the building told Ruptly news agency that she was woken up by a loud bang and saw that all the windows in the apartment were shattered. She immediately detected a strong smell of burning.

"I made a wet cloth mask for my kids, quickly dressed them in warm clothes and grabbed some of my documents," she said.

"We went out right onto the rubble. The whole section of the building was gone."

"We thought an earthquake had happened!" another witness said.

"All the windows were broken - on the balcony, in all the rooms. We heard people screaming."

Some 469 rescuers and 66 pieces of equipment were deployed to the scene. Additional teams, including psychiatric specialists and K-9 units, are being brought from all over Chelyabinsk Region and neighboring Bashkortostan Region.

While the city has deployed its first-response teams, the Emergencies Ministry remains on a standby to fly four planes from Moscow to deliver more staff to the scene.

President Vladimir Putin arrived to Magnitogorsk and inspected the site of the disaster.

The Investigative Committee has launched a criminal probe into the incident.