Preparations for the ZNG began on 12 April 1991. Its formation as a police force with military capability was considered necessary by Croatian authorities after March clashes in Pakrac and at Plitvice Lakes and the possibility of further confrontation with the JNA. Since it was illegal to establish a separate military in a constituent republic of Yugoslavia, the ZNG was planned as part of the police force under the Ministry of the Interior. Parliament amended the Internal Affairs Act on 18 April, and the ZNG was formally established five days later. It was tasked with the protection of the constitutional order, the maintenance of public order, anti-terrorist operations, the protection of Croatia's borders, territory, coast and territorial waters, valuable structures and high-profile individuals. Although the ZNG was formally subordinate to the Ministry of the Interior, its founding legislation stipulated that it would be commanded by the Ministry of Defence.