"We have not so far been approached by the Turkish authorities on the identity of those arrested," the consulate general said.
The Russian embassy spokesman said that they had neither any additional information on the operation by the Istanbul police, nor on the ethnicity of the foreigners and the day when they were taken into custody.
The Turkish media reported the arrest of foreigners in Istanbul on Tuesday. The extremists are said to be linked to radical Islamic groups, from whom they received training in blasting work.
Police also seized a number of electronic devices and drawings of improvised explosive devices (IED). During interrogations, the suspects said they had been intent on shipping IEDs to Chechnya for use in terrorist attacks on federal forces.
There are reasons to believe that the foreigners were arrested on Friday, with two of them having been in Turkey illegally, according to the Turkish media.
