"The command of the Vilayat Dagestan
...a formerly inoffensive Caucasus
republiccurrently bedevilled by low-level Islamic insurgency, occasional outbreaks of separatism, ethnic tensions and terrorism, primarily due to its proximity to Chechnya. There are several dozen ethnic groups, most of which speak either Caucasian, Turkic, or Iranian languages. Largest among these ethnic groups are the Avar, Dargin, Kumyk, Lezgin, and Laks. While Russers form less than five percent of the population, Russian remains the primary official language and the lingua franca...
mujahedeen... declares that the Caucasus fighters are not waging any military activities against the United States of America," theKavkacenter.com website said.
"We are only fighting Russia, which is not only responsible for the occupation of the Caucasus, but also for monstrous crimes against Moslems," the rebel site said.
U.S. media reports said the FBI was studying possible links between the two suspects -- brothers Dzhokhar and Tamerlan Tsarnaev -- to the Caucasus Emirate movement led by feared warlord
Doku Count DokuUmarov
... Self-styled first emir of the Caucasus Emirate. Count Doku has announced that his forces will not target civilians, but qualified that statement by saying there aren't any civilians in Russia...
The reports said the U.S. authorities were particularly interested in the Vilayat Dagestan offshoot of Umarov's group.
Dagestan is a neighboring republic of Chechnya with a large ethnic Chechen minority.
It has also been one of the most violent regions of Russia since the second of two post-Soviet era wars ended in Chechnya about a decade ago.
The Russian authorities said they were also checking the brothers' links to the rebels but had been unable to find any evidence so far.
"At the moment, we have no credible information about the Tsarnaev brothers' involvement with the Caucasus Emirate movement," an unnamed Russian security source told the Interfax news agency.