The separatists starting early July were in possession of at least a single Strela-10 anti-aircraft weapon.
Ukriane Censor.net reported about a Strela-10 seen on a traffic webcam in Luhansk at July 3.
This mobile launcher can reach a target at an altitude of up to 3.500 meters with a horizontal range of max 5.0 km.
At July 11 2015 Dutch newspaper NRC mentioned the Strela-10 in a very good article.
A video posted at vKontakte shows such a Strela-10 on the move in the evening of July 15 around 22:00. The Strela-10 was part of a big separatists convoy travelling East from Donetsk to Snizhne. Part of this convoy was filmed by local residents in Shakhtersk. The video includes a tank, 2 BTR, a Strela-10, three D-30 towed artillery, and numerous trucks and cars before it ends.
At July 16 the Andrei Lysenko, spokesperson of the Ukrainian Defense Minister, confirmed the separatists indeed had a Strela-10. According Lysenko this was proof Russia supplied weapons to the separatists.
A Strela-10 can be seen in this video taken on Donetsk at an unknown data.
Bellingcat found an interesting video made by Russian newsstation Lifenews. The video shows a Strela-10 parked somewhere between Pervomais’kyi and Stepanivka. The Lifenews article was published at July 16.