The memo said the team had spent time in Pakistan and Iran and that one of the women had a relative with a flat in Moscow that might be used as a bomb making factory. Another group of five Islamist militants trained in Pakistan was also expected to cross into Russia soon, it added.
An al-Qaeda linked website said that the group Islamic Caucasus Emirate, led by the rebe Doku Umarov, was poised to claim it had staged the attack. It said that Russia's harsh military measures against independence activists in the Caucasus had provoked the attack. It said: "You disbelievers are the firewood of Hell. You will enter it."