MAKHACHKALA, Russia — Rebels in Russia’s North Caucasus region have denied any link to the April 15 attack on the Boston Marathon in a statement posted on the vdagestan.com website.

“The Caucasian Mujahedeen are not fighting with the United States of America,” according to the statement, which was attributed to unidentified Mujahedeen commanders in Dagestan. “We are at war with Russia, which is responsible not only for the occupation of the Caucasus, but also for heinous crimes against Muslims.”

An FBI-led probe is looking into a six-month trip suspect Tamerlan Tsarnaev, an immigrant of Chechen descent, took around two years ago to Chechnya and neighboring Dagestan, both regions of Russia that have been embroiled in Islamist separatist movements.

Tamerlan, 26, was killed during a gunfight with the police after two explosions on April 15 near the finish line of the Boston Marathon that left three dead and more than 170 people wounded. His 19-year-old brother, Dzhokar, is being held in a Boston hospital where he is in serious condition after being taken into custody April 19.

The website vdagestan.com claims to be the official site of what it terms the “Dagestan Province of the Caucasus Emirate” and features calls for jihad and images of Islamist fighters.