A police official in the Zagreb police department, Davor Posilović, said on Sunday that the police were intensively searching for the organisers of Saturday's march staged by anti-vaccine certificate protesters, since the rally was not officially reported.

The police are also searching for assailants who physically attacked a reporter of the RTL commercial broadcaster while he was covering the demonstrations

Intensive actions are being taken to identify potential organisers and to take appropriate steps against them, Posilović told a press conference in Zagreb on Sunday afternoon.

The failure of organisers to report the rally in advance amounts to the violation of the legislation on public assembly.

The police official added pyrotechnic devices had been used during the rally, the organisers failed to bring security guards and the decision on the restrictions of public assembly was breached.

A report on verbal and physical violence against RTL reporter Goran Latković has been lodged with the police in the meantime.

CCTV and video footage of the incident will be examined to identify the perpetrators and the police will interview all witnesses.

“We are in permanent touch with the Croatian Journalists’ Association (HND) and other professional associations,” Posilović said, adding that all who have any information about the incident can contact the police.

Posilović said that no other incidents targeted against media had been reported to the police.

Nova TV and HTV crews were verbally assaulted at the rally, while a group of protesters took Al Jazeera reporter Nikolina Zavišić’s microphone as she was reporting live.

On Saturday evening a group of protesters moved from Zagreb’s central square to the part of the city where the HRT public broadcaster is located, demanding to see the HRT director and have their rally covered live and calling for an end to “censorship” by the HRT.

Dissatisfied with the way the HRT covered their protest in the central city square at 3 p.m., the protesters shouted “We want elections”, “Referendum and people’s rule”, “Thieves”, “Treason”, “God’s law is above all laws”, demanding to see the HRT director and have their rally covered live. “This is no vaccine, this is poison”, someone in the crowd could be heard saying while some protesters said the world was ruled by “Bill Gates, Talmudists and Soros’s followers”.

The protesters were met by riot police, with a dozen police vehicles blocking access to the HRT building.

Posilović said that demonstrators in the main square also burnt a flag of the ruling Croatian Democratic Union (HDZ) during the protest and that an investigation in this case was under way.