The incident happened on Friday when security guards, deployed by the ruling coalition led by the Croatian Democratic Union (HDZ) and the Croatian Party of Rights (HSP), prevented opposition councillors and reporters from entering the building where the county assembly was voting on a 2006 budget for this county 150 kilometres east of Zagreb.
The HTV reporter Sanja Najvirt was injured when splinters of a broken window pane hit her cheek. She also had bruises on her right shoulder and suffered injuries to her neck spine, the local hospital reported.
"The HND warns of an alarming rise in violence, even political violence, whose victims are more frequently the media and journalists in Croatia," reads the press release issued by the association on Saturday.
"An increasing number of bans imposed on journalists who are prevented from doing their job as representatives of the public has become rampant at the local level, which deserves strong condemnation from civil society organisations as well as appropriate reaction from state institutions as well as from trade unions and political parties," the press release reads.