The Interior Ministry of the Republic of Croatia is a department of the Croatian Government charged with protection of lives and public safety, the personal integrity and property of citizens from illegal acts, maintenance of public order, and other tasks in the scope of domestic affairs under its jurisdiction (Interior Ministry. 2016 Annual Report for 2015, p. 2).

From 1991 to 2002, a part of the Ministry was the Service for the Protection of the Constitutional Order (best known by its Croatian acronym SZUP), with basic task of protecting the constitutional order and providing counterintelligence protection in the entire territory of the Republic of Croatia, preventing activities and violent threats and acts against the state, which included terrorism and organized crime, regardless of whether the persons involved were Croatian or foreign citizens.

According to the Amendments to the Internal Affairs Act enacted on 18 April 1991, the SZUP assumed the activities of the previous State Security Service of the Republic Internal Affairs Secretariat of the Socialist Republic of Croatia. As mentioned on the websites of the Security and Intelligence Agency of the Republic of Croatia, the SZUP “developed into a modern service which did not target citizens of opposing political views, either legally or in practice, but rather protected the constitutional order in the entire territory of the Republic of Croatia against unconstitutional and illegal acts.” The SZUP ceased functioning in March 2002, and its activities were assumed by the Counterintelligence Agency (POA) as one of three new services organised that year by the Security Services Act. The POA operated until 2006, when together with the Intelligence Agency (OA), it was combined into the newly established Security and Intelligence Agency of the Republic of Croatia (SOA).