Two women exploded bombs in the Moscow metro system during the morning rush-hour Monday, killing at least 38 people and wounding 60. The government blamed terrorists from the Northern Caucasus region.
The first explosion occurred at the Lubyanka station, killing about 25 people on the train and platform. The station sits below the headquarters of the Russian Federal Security Service, the agency that replaced the KGB. There was a second blast about 40 minutes later, four stops away at the Park Kultury station.
The Itar-Tass news agency reports 30 of the wounded remain in grave condition late Monday.
Witnesses described mass panic at the two stations after the attacks, with commuters blinded by dense smoke falling over each other as they tried to reach safety.
In a televised meeting with President Dmitri Medvedev, Federal Security Service chief Alexander Bortnikov said early evidence points to terrorists linked to the North Caucasus. No one has claimed responsibility, but last month top Chechen rebel leader Doku Umarov vowed to bring "the war" to Russian cities.
Prime Minister Vladimir Putin broke off a visit to Siberia to return to the capital. He warned that "terrorists will be destroyed."
U.S. President Barack Obama condemned the attacks, calling them outrageous acts. He said the American people stand united with Russia in opposition to violent extremism.
German Chancellor Angela Merkel offered condolences in a message to Mr. Medvedev, while French President Nicolas Sarkozy called the attacks "hateful."
Earlier suicide bombings in Moscow were also linked to separatist rebels seeking Chechnya's independence in Russia's North Caucasus.
Last week, Russian security forces killed a top Islamist rebel leader in the North Caucasus who was blamed for a 2005 attack that left more than 100 people dead in the southern Republic of Kabardino-Balkaria. Police say suspect Anzor Astemirov was killed Wednesday during a routine document check.
The last terrorist bombing in the Russian capital occurred in August, 2004, when a female suicide bomber killed 10 people outside a Metro station. About 40 people died in February, 2004 in a bombing inside the subway.