Answer
The 2010 Moscow Metro bombings and the 2011 Domodedovo International Airport bombing were two major terrorist attacks in Russia for which Doku Umarov, Then-leader of the Chechen separatist group Caucasus Emirate, claimed responsibility. The Metro bombings, which occurred on March 29, 2010, killed 40 people and injured over 100, while the airport bombing on January 24, 2011, resulted in 37 fatalities and numerous injuries.