The fire started after a power cable caught fire in a tunnel leading to the Okhotny Ryad station adjacent to Red Square, the Emergencies Ministry said in a statement.
The ministry said more than 45 people sought medical help and seven were hospitalized. Most of them suffered from smoke inhalation. Thousands were evacuated.
As firefighters were putting out the fire, authorities closed one of the subway lines that cuts through central Moscow. Eyewitnesses say central Moscow streets were thronged with crowds who ended up walking to work.
The subway resumed regular service by noon Moscow time, but half an hour later officials again shut part of the line after they found a smoldering cable at another tunnel next to the Okhotny Ryad station.
The Moscow's subway is an essential transport link, serving up to 7 million people a day. Station or line closures are highly unusual for the network, which has the reputation of being the city's most reliable means of transport.
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