Often, alternatives such as militants, radicals, separatists, etc, may be more appropriate and less controversial, but this is a difficult area: references to the "resistance", for example, imply more sympathy to a cause than calling such fighters "insurgents".
The government fears that a domestic Kurdish separatist movement may be growing, he suggested, and that disenfranchised Kurds could be manipulated by outsiders to destabilize Syria.
Despite the latest measures, Kiev still fears separatist troops may be preparing to move further into the west of the country.
Concerns are rising that the separatists may still be aiming to take Mariupol, a government-held city on the Sea of Azov.
This has led to speculation that ETA, the Basque-separatist terror group, may be planning a ceasefire.
But now, judging by the expanding waistlines of the graying separatist leaders, food may be winning out.
A delegation from the All-Party Hurriyat Conference, the main political grouping of separatists, may soon be allowed to go to Pakistan to obtain the blessings of its government and (less likely) of militant groups based there, most of which oppose a peace process.
Facebook added that nationalist and separatist groups in general may be advocating for something but not necessarily indicating the inferiority of others.
Authorities in the southern Ukrainian city of Sevastopol have installed a pro-Russian mayor as fears grow that the Kremlin may be stoking separatist sentiment in the region.
Shyrokyne lies just 15 miles east of Mariupol, a strategically important port city with a population of near half a million which many fear may be the separatist forces next target.
