Given the complexity of the organization and execution of the attacks US intelligence tend to think that behind them there is no Islamic state, but Al-Qaeda, informs NBC with reference to the high-ranking source of the National Counterterrorism Center.
"It is too early to say whether it is al-Qaeda, IS, or something else, but for sure it was some Sunni groups", the source states.
Sophistication of attack in Paris does not look like the work of the IG, the level of coordination rather points to al-Qaida, he said.
Earlier, ISIS militants claimed responsibility for the attacks in Paris and compared them to September 11.