What is actually the Islamic State Khorasan District?

.2 WEEKS before gunmen stormed the Crocus Town hall near Moscow, killing at least 137 individuals, United States knowledge warned that “radicals” possessed “likely plans” to strike large events in the area. On March 7th Russian security solutions claimed they had foiled a strike through Islamic State (IS), a jihadist company, on a synagogue in Moscow. So it was actually little unpleasant surprise that, hrs after the Crocus Urban area strike, the team claimed accountability.

On March 25th 4 suspects, reportedly from Tajikistan, appeared in court. United States authorities feel they are part of the Islamic Condition Khorasan Province (ISKP). What is this ensemble, and also what threat does it pose?