Soon after crossing the Estonian border the 18. Armee organized the Estonian units fighting against the Soviet forces into security battalions, the Estnische Sicherungs-Abteilungen. The planned structure was a staff of 57 men and four companies of 150 men each.
It was planned to transfer these units to the Ordnungspolizei in May 1942 and reorganize them into Schutzmannschaft Bataillone but that plan was cancelled.
The units were disbanded in October 1942 when the contact time ended. Those who remained in German service were used to form Ost-Bataillone 658-660 and would later end up in the 20. Waffen-Grenadier-Division der SS (estnische Nr. 1).

Estnische Sicherungs-Abteilung 181
Formed in August 1941.

Estnische Sicherungs-Abteilung 182
Formed in August 1941.

Estnische Sicherungs-Abteilung 183
Formed in August 1941.

Estnische Sicherungs-Abteilung 184
Formed in October 1941.

Estnische Sicherungs-Abteilung 185
Formed in October 1941.

Estnische Sicherungs-Abteilung 186
Formed in early 1942.

Sources used

Rolf Michaelis - Estländare i tysk tjänst
Antonio J. Muñoz - Hitler's Eastern Legions: The Baltic Schutzmannschaft 1941-1945
Hugh Page Taylor & Roger James Bender - Uniforms, organization and history of the Waffen-SS, vol 5

Reference material on this unit

- None known at this time -