An Islamist militant group has reportedly said it carried out last week’s bomb attack on a Russian train – on the orders of Doku Umarov, leader of the Caucasian Mujahadeen and one of the country’s most wanted rebels.

The claim published on a website can’t be verified. But previous statements it’s posted by North Caucasus groups have proved correct. The attack on Friday night’s express between Moscow and St Petersburg killed 26 people. The militants’ letter vowed more acts of sabotage against what it called strategic economic targets. The group aims to expel Russian forces from the North Caucasus and set up an Islamic emirate. On Tuesday the funerals took place of some of the attack’s victims, who included government officials and business executives. Nearly a hundred people were wounded. A follow-up explosion on Saturday injured one of the investigators as he visited the scene. Russia has been fighting insurgents in the North Caucasus for more than a decade, following two wars in Chechnya.