MOSCOW, RUSSIA (AFP) - A militant Islamist group claimed responsibility Wednesday for last weekend's deadly Russian train bombing, as investigators said the well-planned attack resembled tactics used by Chechen rebels.
The so-called "Caucasus Emirate," an umbrella group uniting various Islamist factions, said in a statement posted on a Chechen rebel website that it was behind the attack that killed 26 people and injured around 100 others.
"This operation was prepared and executed along with other acts of sabotage, planned from the start of this year and successfully carried out against a set of strategically important sites in Russia, on the orders of Caucasus Emir Dokku Umarov," the statement said.
There was no immediate way of verifying the claim. The statement was posted on KavkazCenter.com, a website that has previously been used as a mouthpiece by Chechen rebels.
Umarov is the self-proclaimed leader of the Caucasus Emirate, which has sought to establish Islamic Sharia rule in Russia's largely Muslim North Caucasus region.
Friday's bombing struck the Nevsky Express, an upscale passenger train running from Moscow to Saint Petersburg, popular with well-off Russians and foreign tourists.
Prosecutors have opened a terrorism probe into the train blast, which was the first major attack to hit Russia's heartland, outside the North Caucasus, since a spate of suicide bombings in Moscow in 2003 and 2004.
The statement on KavkazCenter.com said the train "was mainly used by the ruling bureaucrats of Russia."
At least two government officials were killed in the train bombing, and the chief of Russia's Investigative Committee, Alexander Bastrykin, was injured by a remote-controlled bomb blast when he arrived at the scene the next day.
Bastrykin - whom officials say was not seriously injured - said in a newspaper interview that the bomb that injured him resembled explosive booby-traps laid by Chechen rebels in attacks.
"The second blast at the site of the train disaster could have been targeted directly at the investigative group. Such a tactic has been used by terrorists in the North Caucasus," he told official state newspaper Rossiiskaya Gazeta.
Meanwhile media reports said that police were looking for four suspects of non-Slavic appearance, said to be of a Caucasus ethnicity.
The Kommersant newspaper and the Interfax news agency, citing unnamed police sources, said the four had rented a room in Lykoshino, a village two kilometres from the disaster scene, in the days before the bombing.
Officials were tight-lipped about the Caucasus Emirate's claim of responsibility for the attack.
"We do not comment on such information," an unnamed security official told the ITAR-TASS state news agency.
Chechen rebels have previously issued bogus claims of responsibility, such as one for a deadly August disaster at a Siberian hydro-electric power plant that was later shown to have been caused by a technical fault.
Shortly after the train bombing, an obscure Russian ultra-nationalist group calling itself Combat 18 claimed responsibility for the attack, but both officials and other nationalists said the claim was not credible.
Investigators have said that Islamists were behind a previous bombing of the Nevsky Express, in August 2007, which injured 60 people.
The official death toll in last weekend's train attack was reduced from 27 to 26 on Wednesday, a spokesperson for Russia's emergency situations ministry told AFP.
The toll was corrected after officials uncovered a mistake in identifying the bodies, the Interfax news agency reported.