Detectives in Boston are looking further afield as they piece together their case against Marathon suspect Dzohkhar Tsarnaev.
The uncle of Boston bombing suspect Tamerlan Tsarnaev described his recent visit to Dagestan in Russia and his great shock at the attacks.
Both men were enrolled in a school in Dagestan, a neighbouring region that was drawn into Chechnya's violence during the 1990s.
A jihadist website linked to an Islamist movement founded by a leading Chechan militant said there were no links between the group and the Boston bombings. In a statement, the group said their target was Russia, not America, and that they do not "strike on civilian targets".
The Command of the Province of Dagestan indicates [...] the Caucasian Mujahideen are not fighting against the United States of America. We are at war with Russia. [...]
Also, remember that even in respect to the enemy state of Russia, [...] there is an order by the Emir Dokku Umarov which prohibits strikes on civilian targets.
In this regard, the Command of the Mujahideen of the Province of Dagestan urges the media, primarily the American, to halt speculations and promotion of Russia propaganda.
Residents in the Northern Caucasus state of Dagestan have said they are surprised by the "huge reaction" the attacks in Boston have received across the world.
Dagestan is a focal point of insurgency in the region, where militants wage almost daily violence to establish an Islamist state.
Caucasian Knot, a website dedicated monitoring the violence, says 124 people have been killed and 75 wounded in the first three months of this year across predominantly Muslim Russian provinces, stretching from the Caspian to the Black Sea, including Dagestan and Chechnya.
A young Dagestan resident told Reuters:
Such things are always upsetting but you know this happens every day here. We're surprised by the huge reaction.
Americans think they are some kind of 'super people', like their lives are more important than others.
Tamerlan Tsarnaev kept a low profile during his visit to his family in Dagestan last summer, according to neighbours.
Tamerlan helped his father renovate his apartment next to a dentist is Makhachkala, speaking Russian with an American accent. Madina Abdulayeva described the 26-year-old:
"He was calm, intelligent, handsome, so fashionable. If you were to see him, you'd fall in love with him straight away.
"They say he was a fanatic. I didn't see that. We're all Muslim here. We're all part of Islam. We all pray."
The FBI has confirmed it investigated whether at least one of the Boston Marathon bomb suspects was a follower of "radical Islam" including interviews with Tamerlan Tsarnaev and family members.
In a statement, the FBI said a "foreign government" asked the FBI for information on Tamerlan Tsarnaev.
This request was based on information he had "changed drastically since 2010 as he prepared to leave the United States for travel to the country’s region to join unspecified underground groups".
Both suspects were born in Kyrgyzstan.
The request stated that it was based on information that he was a follower of radical Islam and a strong believer, and that he had changed drastically since 2010 as he prepared to leave the United States for travel to the country’s region to join unspecified underground groups.
The FBI checked... for such things as derogatory telephone communications, possible use of online sites associated with the promotion of radical activity, associations with other persons of interest, travel history and plans, and education history. The FBI also interviewed Tamerlan Tsarnaev and family members.
The FBI said it had not found any terrorism activity, domestic or foreign, and those results were provided to the foreign government in the summer of 2011.
It said the FBI requested but "did not receive more specific or additional information from the foreign government".
Russia asked the FBI to investigate the Boston bombing suspect Tamerlan Tsarnaev in 2011, a US law enforcement official has told Reuters.
The FBI said yesterday that its interview of Tsarnaev, following a tip from a foreign government two years ago, and checks of travel records, Internet activity and personal associations, "did not find any terrorism activity" at that time.
The elder Boston bomb suspect, Tamerlan Tsarnaev died last night in a shootout with police, while 19-year-old Dzhokhar Tsarnaev currently remains in custody.
The FBI has said they will continue their investigation to find out why the suspected bombers allegedly carried out the attack.
Neil Connery reports:
The father of Dzhokhar and Tamerlan Tsarnaev has denied his sons were involved in the Boston bombing.
Anzar Tsarnaev spoke to CNN's Nick Paton Walsh briefly from his car, in Makhachkala, Dagestan.
Anzar Tsamaev, the father of the Boston Marathon bombing suspects, spoke briefly to the media today to say he could not believe his sons were guilty of what they have been accused of.
Speaking from inside his car in Makhachkala, Dagestan, he told CNN: "My sons never did anything."
He also said he was planning to travel to America.