Russian authorities are investigating twin blasts at metro stations in Moscow on Monday that killed 39 people, and have pledged "to wipe out those responsible".
Authorities now are pointing the finger at the Black Widows, an armed group formed by Chechen women after Russia fought two wars with Chechnya in the North Caucusus region in the 1990s.
Many Chechen women allegedly suffered severe brutality at the hands of Russian troops during the conflicts.
Al Jazeera's Divya Gopalan reports on how the attack is one of numerous others the group has been accused of.
Source: Al Jazeera