Demonstrators protested against the construction of a ramp to a private underground car park and the cutting of the trees in the street.

All those detained were taken to police stations and were facing misdemeanour charges. They were banned from approaching Varsavska Street for a week.

The Croatian Employers' Association (HUP) said on Friday the incident was unnecessary and harmful for the overall economic interests of the country, calling on the executive and judicial authorities to ensure investment security, because without it there would be "no new investment initiatives and hence no new jobs."

"The events and images of Varsavska Street send out wrong messages about our country and as such may have long-term negative effects on the selection of Croatia for new investment projects," the HUP said.

It deplored the lack of respect for all the valid permits for construction work to begin, and expressed disagreement with the manner in which the police handled the protest.

"In this country, too, the rule should apply that possession of all required permits is a guarantee for the start of project implementation," the HUP said.

Earlier in the day, the Croatian PEN Centre and the Society of Art Historians condemned the conduct of the police during the protest.