- One of Russia's most-wanted terrorists, head of the Caucasus Emirate militant group and nicknamed 'Russia's Bin Laden'.
- Recently reported to have urged militants to attack the Winter Olympics in Sochi.
- The US State Department offered a bounty of $5m for information leading to his capture.
- claimed responsibility for numerous attacks in Russia, including the 2010 Moscow Metro bombings and the Domodedovo airport bombing in 2011.
- Chechnya's pro-Russian president, Ramzan Kadyrov, claimed Umarov had been killed in January.
Read: Chechen rebel leader 'dies'