Ohrana (Bulgarian: Охрана, "Protection"; Greek: Οχράνα) were armed collaborationist detachments organized by the former Internal Macedonian Revolutionary Organization (IMRO) structures, composed of Bulgarians[1] in Nazi-occupied Greek Macedonia during World War II and led by officers of the Bulgarian Army.[2][3] Bulgaria was interested in acquiring Thessalonica and Western Macedonia, under Italian and German occupation and hoped to sway the allegiance of the 80,000 Slavs who lived there at the time.[3] The appearance of Greek partisans in those areas persuaded the Axis to allow the formation of these collaborationist detachments.[3] However, during late 1944, when the Axis appeared to be losing the war, many Bulgarian Nazi collaborators, Ohrana members and VMRO regiment volunteers fled to the opposite camp by joining the newly founded communist SNOF.[4] The organization managed to recruit initially 1,000 up to 3,000 armed men from the Slavophone community that lived in the western part of Greek Macedonia.[5]
In Greece the Bulgarians reacquired their former territory, extending along the Aegean coast from the Struma (Strymon) River east of Thessaloniki to Alexandroupolis on the Turkish border. Bulgaria looked longingly toward Salonika and western Macedonia, which were under German and Italian control, and established propaganda centres to secure the allegiance of the approximately 80,000 Slavs in these regions. The Bulgarian plan was to organize these Slavs militarily in the hope that Bulgaria would eventually assume the administration there. The appearance of the Greek left wing resistance in western Macedonia persuaded the Italian and German and authorities to allow the formation of Slav security battalions (Ohrana) led by Bulgarian officers.