MOSCOW (AP) — At least eight people have been killed and 12 were injured after a section of a nine-story apartment building in southern Russia collapsed following a natural gas explosion, officials said Tuesday.

Anzhelika Barinova of Russia’s Emergency Situations Ministry says two others are still missing after Monday’s explosion in Astrakhan, 1,300 kilometers (800 miles) southeast of Moscow.

Prime Minister Vladimir Putin, who is running to reclaim the presidency in Sunday’s vote, rushed to the explosion site Tuesday in an apparent bid to demonstrate the government’s quick response to the accident.

He quickly ordered the local authorities to immediately find new apartments for all the residents of other sections of the building, replying to their fears that the entire structure could collapse.

As Putin was inspecting the wreckage, several hundred rescuers continued searching through the debris for those missing.

Putin has ordered local gas company officials suspended pending an official probe, and four of the company’s workers were detained on charges of violation of fire safety rules.

Explosions caused by leaky gas pipes and canisters in Russian apartment buildings are common.