Chechen groups leading the Islamist insurgency against Russia have distanced themselves from the Boston bombings.
Tamerlan Tsarnaev, the elder of the two brothers named as suspects, made a trip last year to the North Caucasus, creating speculation that the men had links to extremist movements in the region.
However a statement from militants operating in Dagestan said:
"Caucasian mujahideen are not carrying out military actions against the United States. We are fighting with Russia, which is responsible not only for the occupation of the Caucasus but for monstrous crimes against Muslims,"
"Even regarding our enemy, the government of Russia, with which the Caucasus Emirate is fighting, the order from the Emir of the Caucasus Emirate Doku Umarov remains valid prohibiting strikes against civilian targets."
The statement also suggested that Russian security services may have been involved in the Boston attacks.
See Reuters for full report.
