"There are several points in the chain of events that need to be checked and used as tests of democratic standards in Croatia," Josipovic told reporters during his visit to the southern coastal city of Split.

"The first test is the decision to put a public property in the service of a private interest. Private interests are welcome, but must not be in conflict with public interests," the president said.

"The second test concerns the decision to begin work and to request a police intervention," he said, recalling the recommendation of the City Assembly to put the construction project under a moratorium until the matter was settled before the Administrative Court.

"This is a serious matter and there should be no rushing. I will personally check each of these points before taking a position on it," Josipovic said.

Josipovic said he had discussed and would further discuss the use of police in this case with Interior Minister Tomislav Karamarko. He added that he would insist on establishing clear criteria for human rights protection in cases of police action.

The police detained 142 protesters for putting up resistance and banned them from approaching the construction site for eight days, the chief of police in Zagreb, Tomislav Buterin, said at a press conference.

Buterin said that the police had been called in by the city government to ensure the beginning of construction work in Varsavska Street. He added that 167 police officers were involved.

Dubravko Teur of the National Police Directorate said that all the people detained were treated well, none of them was injured, there had been no complaints about the conduct of the police, and based on the information so far the police did not overstep their authority.