- 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.
More top news
Northwestern Scotland and Northern Ireland face a rain-hit weekend, while the rest of Britain enjoys some bright but generally dry weather.
All this week while reporting, I have been taking photos. They offer powerful portraits of the lives affected by the desperate outbreak.
Some of the world's biggest football clubs will ask FIFA to move the 2022 World Cup to spring.