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. Last Updated: 07/27/2016

15 Injured in Metro Blast

Russian security services Tuesday appealed for witnesses of a rush-hour bombing in the Moscow subway to come forward with testimony, broadcasting investigators' telephone numbers over television and radio.

Fifteen people were injured in the blast on a platform of the Belorusskaya underground station on Monday night. Some of the seven victims who were hospitalized are in serious condition, said an official at Moscow's ambulance service, speaking on condition of anonymity.

The bomb exploded as a train was pulling into the station, shattering stained-glass mosaics and sending chips of marble from a bench flying into a crowd.

Russia's Federal Security Service, the agency in charge of combating terrorism, said the bomb had an explosive equivalent of 200-400 grams of TNT, according to Andrei Kostromin, an agency spokesman. He declined to release any other details of the investigation.

Mayor Yuri Luzhkov called the explosion a terrorist act, but he did not identify any alleged perpetrators. No claims of responsibility have been made public.

Seven people, including two children, were rushed to a hospital soon after the blast. One more victim went to an emergency room Monday night, and seven people were treated at the scene, the ambulance service official said.

Moscow has seen dozens of bombings over the past several years, but few high-profile cases have been solved.

A bomb exploded in Moscow's Serpukhovskaya subway station in 1996, killing four people and wounding 12.

Bombs destroyed four Russian apartment buildings in 1999, including two in Moscow, and killed about 300 people. Russia's government immediately blamed rebels in Chechnya for those explosions, but there have been no convictions.