[4] As result in September 1916, the Serbian high command sent Kosta Pećanac in the Toplica District to organize a guerrilla uprising.

As a consequence, one of the first measures undertaken by the Bulgarian military authorities was the mass-deportation of non-Bulgarian adult males.

On 12 March, the Bulgarian counterattack started under the command of Alexander Protogerov involving comitadjis' forces of the Internal Macedonian Revolutionary Organisation.

[9] Colonel von Lustig, an Austro-Hungarian liaison attached to the German 11th Army, reported: It is known that most of the Serbian intelligentsia, i.e. functionaries, teachers, priests and others, withdrew with what was left of the Serbian Army, but a certain number of them gradually started to return for psychological or material reasons.

These men were handed over to Bulgarian patrols (usually komitadji) as suspects without any judicial procedure, with the order that they should be "taken to Sofia".

[6]A commission consisting of Colonel Kalkadzhiev, Major Ilkov, Second Lieutenant Yurukov and Sergeant Vitanov, from the 42nd Regiment, 3rd Brigade, 1st Division "Sofia", and Second Lieutenant Simonov and Sergeant Erchikov of the 5th Place Regiment, filtered the deported prisoners in Surdolica and decided on the executions.

[10] At the same time the Bulgarian military authorities killed also many civilians in Vranje, Zajecar, Kacanik, and other places in that area.

[12] The Bulgarian head of the Vranje district described the executed men as "killers, thieves and butchers" whose "[crimes] were so great that at least ten years would be needed to mend their evil".

Drayton noted in his diary that he interviewed fifteen eyewitnesses who charged that Bulgarian forces deported Serbs to Surdulica and executed a portion of them there in accordance with pre-determined lists of names.