In his response to Horvat's letter, Seks joined all members of the Croatian Parliament in condemning the incident.
On several occasions recently Croatian authorities refrained from taking legal and legitimate action against Slovene citizens for violating Croatian customs and police regulations, believing that Slovene authorities would ensure that similar violations were not repeated, the letter said.
Seks said that Wednesday's illegal entry of a group of Slovene citizens into the territory of the Republic of Croatia and their attempt to illegally leave the country, refusing to identify themselves and offering resistance to the Croatian police in the pursuance of their duties, represented a serious incident.
Seks noted that the Croatian police were doing their job in line with their authority after the Slovene citizens had evidently violated the existing customs and police regulations on the territory of the Republic of Croatia.
As particularly worrying and disturbing Seks cited the fact that among those involved in the incident were members of the Slovene Parliament.
The letter said that Slovenia and Croatia were neighbouring and friendly countries which had to resolve their outstanding issues in a manner common to all democratic countries.
Seks said in conclusion that ignoring and violating the existing laws of the Republic of Croatia by members of the Slovene Parliament would certainly not contribute to the further promotion of bilateral relations. He emphasised that Croatia had never given nor would it give reasons for incidents and tension in relations between the two countries.