A Ukrainian Air Force's MiG-29 multirole fighter aircraft was reportedly shot down by pro-Russian rebels in the Luhansk region on 17 August.
Ukrainian Defence Ministry spokesman Leonid Matyukhin was quoted by Agence France Presse as saying: "In the course of an assignment to eliminate a large group of terrorists, an MiG-29 was shot down this morning in Lugansk region.
"The pilot ejected and was transferred to a safe place once the search-and-rescue measures had been taken."
Several Ukrainian Mig-29 Fulcrum fighter jets returned to operational service in April, days before Ukraine launched an offensive against pro-Russian militia who are demanding greater autonomy from the country, reports RIA Novosti.
Manufactured by Mikoyan design bureau, the MiG-29 Fulcrum is a fourth-generation jet fighter aircraft designed to destroy hostile air and surface targets within radar coverage limits using unguided weapons during visual flight conditions.
The MiG-29 downing comes as Ukraine accuses Russia of supplying anti-government protestors with a convoy of rocket launchers, reported Al Jazeera.
Ukrainian military spokesman Andriy Lysenko said Russia had sent more than three Grad missile systems to separatists in eastern Ukraine.
Moscow has consistently denied allegations that it is supplying equipment or training to rebels.
The country is currently sending a humanitarian aid convoy comprising water, food and medicine to suffering civilians in the eastern Ukraine.
However, the Ukrainian and Western governments claim that the convoy might be a pretext for moving military supplies to insurgents or sending in the 20,000 Russian troops that are believed to be waiting on the Ukrainian border.
Since June, Pro-Russia rebels are reported to have brought down several Ukrainian military aircraft, including Sukhoi Su-25 fighters and an Antonov An-26 transport plane.
Meanwhile, heavy fighting is underway in Luhansk with Ukrainian Security Forces taking control of a rebel-controlled police station in neighbouring Zhovtneviy.
The Russian, Ukrainian, German and French foreign ministers were scheduled to hold meeting on the Ukraine crisis in Berlin, Germany, yesterday.
Image: A Ukrainian Air Force's MiG-29 multirole fighter aircraft in flight. Photo: courtesy of Mike Freer - Touchdown-aviation.