"The police conduct was entirely legal and the use of means of coercion was justified," Bukvic told a news conference.
After the incident, police chiefs were informed in detail about the incident and they decided that there was no need for an internal investigation, Bukvic added.
The Croatian police on Wednesday arrested 12 Slovenian citizens, including several officials of the Slovene People's Party, who illegally crossed the Slovene-Croatian border near the Plovanija border crossing.
The incident has provoked political reactions in Croatia and Slovenia, and the European Commission has voiced concern.