A government official said that Serbia may ban political groups uttering threats against others, such as ultranationalists whose vociferous opposition led to canceling a gay rights march.
Junior justice minister Slobodan Homen told B92 television that authorities were planning to ask Serbia's top court to "ban all organizations that voice threats."
He singled out the small ultranationalist group Obraz (Honor) and the Serb Popular Movement 1389.
Organizers canceled the event after authorities suggested a different venue away from the city center for security reasons.
Nationalists later hailed the cancellation saying it was a defeat for "infidels and Satanists".
Belgrade Mayor Dragan Djilas on Friday also came out in favor of outlawing "groups and organizations that condone violence".
Also speaking on B92 television, Serbian police chief Milorad Veljovic Monday pledged that "stricter measures" would be taken against people who approve violent behavior.
Veljovic said that "37 people were arrested" Sunday after they tried to stage an anti-gay rally in central Belgrade following an appeal by the ultranationalist Serb Popular Movement 1389.
Five people would be brought to justice, four had already been sentenced and the others would be fined, he added.
Serbian police had turned out in force Sunday to break up the protest.
The gay march would have been the first for nearly a decade since the last one in 2001 broke up amid violent clashes with right-wing extremists.