Russian media reports the Boston bombing suspects are ethnic Chechens, although it's unclear exactly which region they're from.
The Associated Press reports that the 19-year-old fugitive Dzhokhar Tsarnaev was born in a region near Chechnya. A page on VKontakte, Russia's version of Facebook, bearing his name and what appear to be photographs of him, says he was a student in a school in Makhachkala, the capital of the Dagestan Region next to Chechnya from 1999 to 2001.
On his social media profile, Dzhokar is a follower of groups relating to Chechens and says his priorities are his "career" and "money."
Radio Ekho Moskvy reports that teachers at the school say they don't remember Tsarnaev from his one year there.
The website Gazeta.ru reports that he was a student at Cambridge Ringe & Latin School after he left Makhachkala.
Other websites say his 26-year-old brother Tamerlan, who is believed to have been killed by police on Friday, was born in Chechnya before his family fled war there in the 1990s. He's said to have lived in Kazakhstan before receiving political asylum in the United States.
Their uncle, Ruslan Tsarni of Montgomery Village, Md., told the Associated Press that both boys had lived in the United States since around 2001 but that has not been confirmed.
Tsarni told a local CBS station that he had not been in touch with the boys since 2009 and described Tamerlan as a "loser."
Another one of the boys' uncles said that they had been out of touch for years until he received a call yesterday asking for forgiveness.
A photo essay of Tamerlan Tsarnaev by photographer Johannes Hirn describes his ambition to compete for the US Olympic boxing team.
Tamerlan also describes himself as "very religious."
He said that he would not fight for the Russian Olympic team as long as it held Chechnya.
Moscow fought a war to subdue separatist Chechnya from 1994 to 1996, when rebels forced Russian troops out of the region. Then-Prime Minister Vladimir Putin launched a second war there in 1999.
Now run by Kremlin-installed strongman Ramzan Kadyrov, however, Chechnya is more stable than the surrounding regions, where violence and instability have spread.
Years of civilian deaths and atrocities have helped nurture Islamist militancy in Chechnya and surrounding regions.
Dagestan is now considered the most volatile region. Locals live under a heavy military presence and suffer regular human rights abuses. Shootings and bombings by militants take place there almost daily.
The Kremlin links its campaign against local militants to the global campaign against terrorism.
Chechens have been involved in violence outside the regions before, including a hotel bombing in Istanbul in 2001.
However, there's no evidence yet that the Boston bombing suspects, who have lived in the United States for a number of years, had any links to extremist groups.