Rescue workers have pulled eight bodies from a collapsed apartment building in Moscow following an explosion late Tuesday. VOA's Rebecca Santana reports from the Russian capital.

The blast ripped out one section of a five story apartment building in northern Moscow. Rescuers worked through the night searching for people in the debris.

The Russian Deputy Interior Minister, Vitaly Mozyakov, said investigators are looking into the cause of the explosion. He said a natural gas leak or a terrorist act could have caused the blast.

Many apartment buildings in Moscow use natural gas for cooking and gas leaks from the antiquated pipes and stoves often cause fires or explosions.

Local residents earlier reported that they smelled gunpowder after the explosion, sparking concerns that it could have been a terrorist act. But since then, Russian officials indicated natural gas is the most likely cause.

The apartment blast was reminiscent of a series of explosions that shocked Russia in 1999 and killed about 300 people.

At the time, the Russian government blamed the explosions on Chechen terrorists and used the blasts as a reason for invading the breakaway region of Chechnya.

Monday, 115 people were killed in a helicopter crash in Chechnya. An Mi-26 helicopter was ferrying troops to Khankala, a military base in Chechnya when the helicopter crashed in a minefield.

Investigators are trying to determine why the helicopter crashed. They are looking into two possible causes - a mechanical failure or a rebel attack.

Russian President Vladimir Putin has declared Thursday to be a day of mourning for the crash victims.