"We know that the crime was committed by the hands of radical Islamists, whose ideology the Islamic world itself has been fighting for centuries," Putin said on Monday at a meeting on measures taken after the terrorist attack.

The Russian President said it is already known who carried out the terrorist attack, but now "we are interested in who ordered the crime", Xinhua news agency reported.

He said that the US, through various channels, is trying to convince everyone that there is supposedly no Kiev trace in the bloody terrorist attack.

However, Putin believes questions still remain. "It is necessary to obtain answers to a number of questions, for example, are radical, even terrorist, Islamic organizations really interested in striking Russia, which today stands for a fair solution to the escalating Middle East conflict," he said.

Putin also noted that it is necessary to answer the question of why the terrorists tried to go to Ukraine after committing a crime in Crocus, and who was waiting for them there.

Calling the attack an act of intimidation, Putin said, "The question arises who benefits from this."

The investigation into the terrorist attack should be carried out to the highest degree professionally, objectively and without political bias, despite the general desire to punish the perpetrators, Putin added.