Chechen rebels say they blew up Russian dam - web
"Glory to Allah, on August 17 through our efforts, a subversive operation was carried out in Khakasia at the Sayano-Shushenskaya hydro-electric dam," said the letter from a group calling itself the Martyrs' Battalion.
"In the machine hall we managed to plant an anti-tank grenade with a timer, the blast of which caused much stronger damage than we could have hoped for," said the letter, which was published on the www.kavkazcenter.com website.
(Reporting by Guy Faulconbridge; Editing by Kevin Liffey)