UPI en Espanol  Russia denies links between bombing suspects,
extremist groups  April 21, 2013 at 7:16 PM MOSCOW, April 21
(UPI) -- Russian officials have denied links between the
suspects in the Boston Marathon bombing and extremist groups in
the North Caucasus.  Investigators in the United States were
looking into possible connections between the suspects --
brothers Tamerlan Tsarnaev, 26, and Dzhokhar Tsarnaev, 19 --
ethnic Chechens who immigrated to the United States more than 10
years ago, USA Today reported.  Tamerlan Tsarnaev, who was run
over by his brother during a shootout with police, allegedly had
content on his YouTube account that led investigators to believe
he may have been involved with North Caucasus extremist groups,
such as the Caucasus Emirate.  The older Tsarnaev also followed
radical Islam, an FBI news release indicated.  However, a
Russian law enforcement official told RIA Novosti the brothers
did not have a direct link to any extremist groups.  Russian
military expert Vladislav Shuryg