The Special Anti-Terrorist Unit of Ministry of Interior of Republika Srpska (Serbian: Specijalna antiteroristička jedinica Ministarstva unutrašnjih poslova Republike Srpske, SAJ; Serbian Cyrillic: Специјална антитерористичка јединица Министарства унутрашњих послова Републике Српске, САЈ) is a special police and security force unit of the Police of Republika Srpska, one of two autonomous entities that comprise Bosnia and Herzegovina.

In that time, brigades command was in Janja near Bijeljina and unit was divided on nine battalion-sized detachments : Every detachment was capable to be independent on battle field because of its organisation.

[2] Second development stage is considered for peace time when command was in Janja and when brigade was renamed into Specialized Police Service (Служба специјализоване полиције).

On 2004 service changed name into Special Police Unit (Специјална јединица полиције or СЈП) and next year base was moved in central base "Sarica" in Trn near Banja Luka.

Today, the SAU is the most elite unit of Ministry of Interior of Republika Srpska and cooperates with other special units in region and Europe, like the Serbian SAJ, PTJ and Gendarmery and Slovene SEP, French GIGN German GSG 9, Italian GIS.