The causes of the blasts were not immediately clear, but the government said it suspected suicide bombers, Russian news agencies reported.
The subway system, one of the world’s most extensive, had been subjected to attacks related to the separatist war in Chechnya in the early part of the last decade.
Officials said the first explosion Monday occurred at 7:50 a.m. in the Lubyanka subway station, killing 19 people both on the platform and aboard an incoming train. Numerous others were injured.
“The blast hit the second carriage of a metro train that stopped at Lubyanka,” Irina Andrianova, a spokeswoman for the emergency ministry, told Reuters.
About 40 minutes later, another explosion occurred in the second car of a train at the Park Kultury station, killing 14 people, officials said.
In September 2004, a suicide bomber killed at least 9 other people and wounded more than 50 outside the Rizhskaya subway. In February of that same year, a woman carrying a bomb destroyed another subway car, killing at least 41 people as the train moved between the Paveletskaya and the Avtozavodskaya stations at one of the busiest times of the day.
The Lubyanka station, where the first explosion occurred, takes its name from the infamous Lubyanka prison that also served as the former headquarters of the K.G.B., the Soviet-era secret police.