30 people requested medical aid; and more than 20 persons were rushed to hospital, reports the municipal civil-defense and emergency-situations department.
Passengers, who suffered as a result of the blast, are currently being evacuated via the Paveletskaya and Avtozavodskaya stations.
The blast occurred at 8.45 a.m., that is, during the rush hour, while the train was moving from Paveletskaya to Avtozavodskaya along the Zamoskvoretskaya line. Moscow residents usually ride to work at this time.
A terrorist act seems possible, Sergei Ignatchenko, chief of the Federal Security Service's public-relations center, told RIA-NOVOSTI.
In his words, investigators are now working at the scene; moreover, a coordinating center has been established for investigating this outrage.