The USA, the UK and Ukraine are involved in the terrorist attack at Crocus City Hall, Federal Security Bureau Director Alexander Bortnikov said, TASS reports.
According to the official, intelligence services of the United States and Britain, as well as the Main Intelligence Directorate (GUR) of Ukraine, were involved in organising the crime.
The FSB director stated that the purpose of their participation in organising the terrorist attack was to destabilise the situation in the Russian society.
"We are now talking about the facts that we have at our disposal. This is general information, but there are already certain developments,” he noted.
The FSB and intelligence services of friendly states are identifying all participants in the terrorist attack, he added.
Earlier, Russian Foreign Ministry spokeswoman Maria Zakharova said that statements from US officials about Ukraine's non-involvement in the terrorist attack could be considered evidence. In her opinion, until the investigation is completed, any phrase from Washington justifying Kyiv should be considered as evidence.
The attack on the Crocus City Hall concert hall in Krasnogorsk near Moscow was prepared by the Islamic State group (ISIS, a terrorist organisation, banned in Russia), FSB Director Alexander Bortnikov said adding that the Security Bureau of Ukraine (SBU) assisted the radical Islamists.
According to Bortnikov, Ukraine trained militants in the Middle East.
"We know that the Ukrainian side trained militants in the Middle East,” he said.
The FSB director said that the SBU should be considered as a terrorist organisation after what happened at Crocus City Hall.
"We should do this, of course, yes. I believe this is the basis. Not only to consider it as such, but to make appropriate decisions," Bortnikov said.
Kyiv was ready to welcome the terrorists as heroes, the FSB director noted stressing out the fact that the criminals intended to hide on the territory of Ukraine.
"According to our preliminary operational information, they were waiting for them there… I'll tell you a little secret: they wanted to greet the terrorists as heroes there," Alexander Bortnikov said.
The shooting at Crocus City Hall occurred on the evening of March 22. All the perpetrators of the terrorist attack were detained in the Bryansk region of Russia as they were trying to escape to Ukraine.