The Serb population revolted against oppression by the Ustaše regime, the rulers of the Independent State of Croatia who were sponsored by Nazi Germany.

[8][9][10][11] Oppression by the Ustaše regime was directed at Serbs, Jews, Muslims and Roma people, as part of a larger campaign of genocide.

[12][13] In Sanski Most, NDH officials, including Viktor Gutić, commissioner incited local Croats and Muslims to attack Serbs.

On 23 April 1941, Gutić ordered all Serbs and Montenegrins living in the Bosanska Krajina, who had been born in Serbia or Montenegro, to leave the area within five days.

[16] Oppression by the Ustaše regime caused spontaneous resistance by civilians which developed into armed uprisings in villages south-east of Sanski Most.

[17] [18] On 6 May 1941, hostilities were precipitated by Ustaše (mostly Muslims) breaking into houses of Serb civilians in Kijevo and Donja Tramošnja.

[22] The Serb civilians chased away the Ustaše who escaped to Kijevo and Sanski Most and requested help from the German garrison in Prijedor.

[23] On the morning of 7 May 1941, Ustaše authorities imprisoned several notable Serb civilians in the army barracks at the railway station.

[30] The Serb civilians from Kijevo, Vidovići, Tramošnja, Kozica and other neighbouring places quickly took defensive positions on the slopes of Kijevska Gora above Sjenokos.

One company of 132 Pioneer Battalion traveled by bicycle and one motorised battery from Kostajnica joined Henig's forces.

[35] On 8 May 1941, the German force was strengthened by motorized infantry from Bosanski Novi and a battery of two cannons from the Artillery division garrisoned in Prijedor.

[38][39][40] After shelling Tramošnja and Kijevska Gora (a mountain near Kijevo), the German forces moved toward Tomina, Podovi and Kozica villages.

However, the German forces did transport about thirty Serb prisoners from the Tomina area to Sanski Most, even though they had not individually participated in the hostilities.

[48] Until the end of July 1941, most of the leaders of the Đurđevdan uprising hid in a wooded area near Kmećani and planned their next action.