[From the book “Nationalism and Communism in Macedonia) by Evangelos Kofos, Institute for Balkan Studies, pages 108-110]
Contrary to Greek Macedonia, the Bulgarians were received here, on the whole, by a friendly population. Historical ties uniting the Slav populations on both sides of the frontier, and Bulgarian propaganda which had not ceased during the inter-war years, had kept alive the pro-Bulgarian feelings of the inhabitants.
The Bulgarian authorities made no secret of their cooperation with the Bulgaro-Macedonian nationalists, especially the followers of the I.M.R.O., many of whom had joined special Bulgarian armed units to assist in the policing of the region.  The task of forming these units was assigned to General Ivan Marinov who accepted in his staff two I.M.R.O. liaison officers named Grupcev and Nastev.  At the same time, a Bulgarian nationalist organization named cOpstestvena-Cila," was entrusted with the task of preparing the ground for the eventual, gradual integration into Bulgaria of the districts not included in the Bulgarian zone of occupation. Political committees of this organization were set up in Tetovo, Gostivar, Kicevo, and Debar 
However, despite the fact that all the prerequisites for the success of the Bulgarian objectives existed, it became increasingly evident that the native population was daily becoming disillusioned with the Bulgarians. A variety of reasons could be cited for this unexpected development. The most important was, apparently, the fact that the Slav peasants were surprised by the misconduct of the Bulgarian soldiers, who, far from acting as liberators, were frequently involved in situations very common in an army entering a foreign country. The Bulgarian authorities tried to correct the situation, but the first bad impressions remained. Then came stern reprisals by the Bulgarian occupation authorities, sometimes against innocent peasants, for murders of Bulgarian soldiers and officers committed by communist partisans. In April 1942, the communists attempted an uprising in the Monastir-Prilep district which was put down by the Bulgarian Army and Gendarmerie executing twelve local communists. The population reacted with mass demonstrations causing the death of the Bulgarian Gendarmerie commander and 15 gendarmes. In turn, the Bulgarians executed many villagers, men and women. 
Rather than project the elements held in common, these developments tended to stress those dividing the inhabitants of Yugoslav Macedonia from the Bulgarians. The strong regionalist spirit revolted against the lordly attitude of the Bulgarian authorities, a fact properly exploited by the communists, as will be seen in a subsequent chapter. The Bulgarians were, thus, engaged in a chain reaction, since reprisals against the partisans drove the native Slavs even farther away from Sofia and into the arms of the communists who were fighting under the slogan for a "Macedonian state" within Yugoslavia.
The last attempt by nationalist Bulgarians to win over Macedonia came when the Germans were preparing to withdraw from the Balkans. Ivan Mihailov, chief of the I.M.R.O. who had maintained friendly relations with the Nazis, attempted to establish an autonomous Macedonian state 
But history had outrun him and rendered his plan outdated. Now the initiative had definitely passed to the communists who began to exhibit their lively interest in the potentialities of Macedonian politics.
- Barker, op. cit., p. 78.
- "Filov's Diary," Otetsestven Front, op. cit.
- Barker, op. cit., p. 79.
- "The trial of the I.M.R.O. followers in Sofia, August, 1946," Glas (Belgrade), August 19, 1946.
- Secret Report, GFM, A/24317/2/1949.
- "Monthly Confidential Report of the [Greek] Ministry of Interior," May 1942. In GFM Archives.
- Makedonska Tribuna, (Indianapolis, U.S.A.), organ of Mihailov's (I.M.R.O.) followers in the United States, wrote in February 22, 1951 that in the closing months of the German occupation, Mihailov had many talks with Bulgarian officials in Yugoslav Macedonia. In his talks he tried to convince them of the wrong policy they pursued trying to annex Yugoslav Macedonia to Bulgaria. Mihailov argued that the best course was first to adopt an autonomous status for Macedonia. Bramos, [First Edition], op. cit., p. 136.