آژانس‌های امنیتی اروپا تحقیق می‌کنند که آیا دروغ‌های بمب‌گذاری در روسیه آغاز شده است یا خیر

European security agencies probe whether bomb hoaxes started in Russia

A working hypothesis is that the co-ordinated threats were produced by pro-Kremlin activists or hacking groups