I've seen before that Jihadis were operating in Ukraine on the Kiev side, but this is a good overview article (excerpts):
If the Ukrainian regime is now openly acknowledging getting aid from unnamed countries, it’s fair to ask: is the Dudayev Battalion getting direct aid from the same sources supplying Syria’s radical Islamist rebels with arms – Qatar, Kuwait, the United Arab Emirates, and the Saudis?
The Dudayev Battalion numbers around 500 fighters, but there are also other jihadist brigades in Ukraine, organized into "the Sheikh Mansour battalion, which broke off from the Dudayev battalion" and "is based close to Mariupol, in the southeast of Ukraine," as well as two other groups composed of Crimean Tatars, each consisting of about 500 jihadists.
As US aid flows into Ukraine, how much of it will trickle down to these allies of ISIS – and to what future use will it be put? If John McCain and Lindsey Graham have their way, US arms will soon find their way into the hands of these terrorists, whose jihad against the Russians is bound to turn westward and strike at the capitals of Europe.
This is blowback with a vengeance: we are creating our own enemies, and giving them the weapons to harm us, even as we claim the need for universal surveillance in order to fight them. The mad scientists formulating US foreign policy are raising an army of Frankenstein monsters – who are sure to come after their deluded creators.