MOSCOW (BNO NEWS) — Chechen rebels on Friday claimed responsibility for the Russian dam disaster which killed more than 70 people this week. The statement, from a group calling itself the Martyrs’ Battalion, was posted to a rebel website.

“Glory to Allah. On August 17, through our dedication, sabotage was carried out in Khakasia at the Sayano-Shushenskaya hydro-electric power station,” the statement read. “The plan, on which we worked a long time, was carefully thought out.”

According to the group, it placed an anti-tank grenade in the engine room of the plant, causing a “greater loss than we had hoped for.” The official cause of the disaster is still unclear but a Russian investigation committee said on Friday that no traces of explosives have been found.

The letter also claimed responsibility for a recent bomb attack in Russia’s Ingushetia which claimed the lives of some 20 people, and injured scores of others. The operation caused kafir (an Arabic word meaning rejecter, generally someone who does not recognize Allah or the prophethood of Muhammad) a big hit, and therefore the work in this direction will continue at the will of Allah,” the group said. “We declare our responsibility for these operations and its planning.”

The rebels stressed it was trying to limit civilian casualties in its operations, but said that some civilians had been injured. “Until now, many are missing and their relatives have stormed the hospital and morgue, while the bodies were torn into small fragments and then burned in a fire.

“Today we give you the opportunity to pardon and quietly leave the service of Kafir, and then we will stop to harass and destroy you.”

The group further said that it decided, early this year, to intensify the “economic war” against Russia and its territory. The rebels claim fighters have been sent to several Russian regions to carry out sabotage at mainly gas pipelines, power plants, power lines and at factories.

Meanwhile, a Kremlin source told the Reuters news agency that it would not comment on the “idiotic” claims.