One of the suicide bombers from each of the Moscow and Dagestani blasts has been identified, local media reported on Thursday.
A female suicide bomber who blew herself up at Moscow's downtown Cultural Park metro station on Monday has been identified as a resident of the restive North Caucasus republic of Dagestan, said an anonymous source in the North Caucasus Federal District security service.
The bomber's name was not revealed to safeguard the ongoing investigation, said the source as reported by the RIA Novosti news agency.
Both female suicide bombers in the Moscow attack had been confirmed as being linked to groups in the North Caucasus. The identity of the other female suspect remained undisclosed.
Meanwhile, the Interfax news agency says the Russian Interior Ministry has identified one of the suicide bombers responsible for Wednesday's twin blasts in the Dagestani town of Kizlyar as a local resident named Daud Magomedov, or Daud Jabrailov.
"According to the preliminary information, local resident Daud Jabrailov dressed in a police uniform and set off the bomb. He was identified by body fragments," said an official from the Dagestani department of the Investigative Committee of Russian Prosecutor General's Office, Nizami Rajabov.
The second suicide bomber has also yet to be identified.
On Monday, two female suicide bombers killed 39 in attacks on the Moscow subway system.
On Wednesday, 12 people, including nine police officers, were killed in two blasts in the Dagestani town of Kizlyar.
Russia's North Caucasus republics, particularly Chechnya, Dagestan and Ingushetia, have been plagued by violence, particularly against law enforcement officers, which local rebels see as representing the Russian authorities.