"The fire was extinguished at 1:18 p.m. [10:18 a.m. GMT]," he said.
One person received multiple burns to his face and hands, while another suffered carbon monoxide poisoning.
Four people trapped in the building after the blaze caused the roof of the Dyagilev nightclub to collapse have now been rescued.
It took 35 firefighting units and a helicopter less than two hours to put out the blaze, which spread over an area of 1,500 square meters (around 5,000 square feet).
Another emergencies ministry spokesman, Yevgeny Bobulyov, said that firemen arrived three minutes after being informed of the blaze, but the building had already been engulfed by flames.
Top emergencies ministry officials, including Emergency Situations Minister Sergei Shoigu, also arrived at the scene of the fire.
The head of the Emergency Situations Ministry's firefighting department, Mikhail Verzilin, ruled out the possibility of arson, saying that the fire had been caused either by welding work or a malfunction of the club's electrical wiring.
The fire broke out two and a half hours before the Chinese embassy in Moscow was scheduled to celebrate Chinese New Year in the nightclub.
