I wonder if these Islamist insurgents are being covertly armed and financed by the US/NATO. The US/NATO is now openly arming Al Qaeda to attack Syria and it would not be the first time the US/NATO used Islamic insurgents to attack Russia.
Russia/USSR started that crap in the early 1970s using Muslim fighters PLO, ANO, PLFP etc. Continued later in Iran...to overthrow the Shah.
The Soviet-backed Sandinistas also got into the airliner hijacking thing, training with Soviet backed Muslim terrorists.