At least 37 people have been killed in two explosions on Moscow's subway system during the morning rush hour.
The two blasts, thought to be suicide bombs, appear to have been co-ordinated.
The first explosion took place at 7.56am local time (3.56am GMT) at the central Lubyanka station. Officials said that the dead included 14 train passengers and 11 people on the platform.
The second blast, about 40 minutes later at the Park Kultury station, killed 12 people.
The Russian authorities have said that these were "terrorist" attacks.
No-one has yet claimed responsibility, but suspicion has initially fallen on Islamist insurgents from the volatile North Caucuses region. Russia has waged a brutal campaign against this insurgency in Ingushetia, Chechnya, and Agastarn.
The last major attack on the Moscow Metro, which carried 5.5 million people every day, was in February 2004, when 39 people were killed. The attack was blamed on Chechen rebels.
