Russian security forces killed three people suspected of organizing the March 29 suicide bombings in the Moscow metro, in which 39 people died, an official said May 13.

Security forces attempted to detain the three but killed them when they resisted, the chief of the Federal Security Service, Alexander Bortnikov, told President Dmitry Medvedev.

"Unfortunately, we were not able to detain them alive," Bortnikov said, without specifying when or where the killings of those allegedly linked to the Moscow attacks took place.

AP