Starstreak is a portable surface-to-air missile installation, rockets of this build are the fastest of their kind. It fires three tungsten spears at the target. They can reach speeds of Mach 3. A YouTube video would show these heavy metal arrows breaking off the tail of a Russian helicopter in the skies in the Luhansk region.
A source from the British Ministry of Defense newspaper believes the video does indeed show Starstreak impacts. The anti-aircraft weapon is said to have been delivered to the Ukrainians a week ago.