In these minutes Fligthradar24 is tracking an unknown plane orbiting over Gökçeada island, off Dardanelles.
The aircraft is flying at 26.000 ft between 500 and 700 kts. The ICAO code is 000970 and the callsign is HM55 (?).
We do not know what kind of aircraft it is but, given the speed, it is possible that it is a figther.
(thanks to Bolzano twitter account)