Separatist fighters shot down a Mi-24 helicopter of the Ukrainian Air Force in Luhansk region on August 20, and its crewmembers were killed, the Ukrainian National Security and Defense Council (NSDC) has reported.

"On August 20, near the village of Heorhiyivka in Luhansk region, during the fulfillment of a combat task, terrorists shot down a Mi-24 helicopter, and the crew members were killed," NSDC spokesman Andriy Lysenko said at a briefing in Kyiv on Friday.

He noted that the National Security and Defense Council had not reported this intentionally so as "to conduct a search operation and bring the bodies of our pilots to our territory."

Lysenko did not specify the number of those killed.

The Mi-24 is a military transport helicopter. The crew usually consists of two or three persons: a pilot, a weapons operator and in some cases a flight mechanic.