Head of the 8th Directorate of the General Staff of the Armed Forces of Russia, Lieutenant-General Yuri Kuznetsov ordered to suppress cellular signals (2G and 3G) in the territories of two Russian bases in Syria - Khmeimim and Tarus.
The document was signed on February 2, and its operation should be provided until March 30, 2018.
http://censoru.net/24985-rossiyskih-voennyh-otrezali-ot-mira-v-sirii-chto-sluchilos.html
A detailed description