[citation needed] Estonian units were first established on 25 August 1941, when under the order of Field Marshal Wilhelm Ritter von Leeb, commander of the Army Group North (Heeresgruppe Nord), Baltic states citizens were permitted to be recruited into Wehrmacht service and grouped into volunteer battalions for security duties.

[1] In this context, General Georg von Küchler, commander of the 18th Army, formed six Estonian volunteer guard units (Estnische Sicherungsgruppe, Eesti julgestusgrupp; numbered 181–186) on the basis of the Omakaitse squads (with its members contracted for one year).

After September 1941, the Oberkommando der Wehrmacht (Armed Forces High Command) started to establish the Estonian Auxiliary Police Battalions ("Schutzmannschaft" (Schuma)) in addition to the aforementioned units for Bandenbekämpfung (countering resistance and rear security) duties in the Army Group North Rear Area (Rückwärtiges Heeresgebiet Nord).

The police battalions were mostly engaged in the Wehrmacht Army Group Rear Area Command (Befehlshaber des rückwärtigen Heeresgebietes).

As their largest operation, supported by the 3rd Battalion of the Estonian Waffen Grenadier Regiment 45, they destroyed the Kärevere bridgehead of two Soviet divisions west from Tartu and recaptured the Tallinn highway bridge over the Emajõgi by 30 August.