Rescuers are evacuating casualties from two stations of the St. Petersburg metro, Sennaya Ploshchad and Tekhnologichesky Institut, where explosions were earlier reported.

"Tentative reports indicate that the explosions seriously damaged one car at each station, and casualties are being evacuated from both the wrecked cars and from the metro stations themselves," a source in the emergency services told Interfax.

The victims have suffered numerous fragmentation wounds presumably caused by striking elements of the explosive objects, the source said.