Russian President Vladimir Putin said that if the Russian plane A321 fell victim of a terrorist attack the traces of explosive would inevitably have been found.

"If there were an explosion, the traces of explosive should remain on the plane covering and the things of passengers. This is inevitable," Putin said at a press conference, following the G20 summit.

Meanwhile, he noted that no theory behind this tragedy was brushed away so far. "We are aware of all theories, all theories are being considered. Final conclusions should be drawn after conducting and completing expertizes," the head of state said.