The demonstrators attacked the journalists because they were angry at local media coverage of Milosevic's extradition to the international war crimes tribunal in The Hague.
"The Serbian government must promptly investigate and prosecute the individuals responsible for these incidents, and also ensure that police officers are more responsive to the physical safety of journalists in the future," said CPJ executive director Ann Cooper.
The attacks against journalists occurred in Belgrade's Republic Square, where several thousand supporters of Milosevic's Socialist Party of Serbia (SPS) and the allied Serbian Radical Party (SRS) were protesting the sudden extradition of Milosevic earlier that day.
The first attack occurred before 7 p.m., when reporters from the Studio B television station were approaching the rally. Several men approached the journalists and punched cameraman Milos Petrovic, knocking him to the ground.
At approximately 10 p.m. Beta news service reporter Suzana Rafailovic was interviewing an SPS activist when several people approached to inquire which media outlet she worked for, Beta editor-in-chief Dragan Janjic told CPJ. When the SPS activist responded that the journalist worked for Beta, the men started threatening and manhandling her.
About 30 minutes later a group of SPS supporters assaulted Petar Pavlovic, a photographer with the local news agency Fonet, when he approached the rally to take some pictures, Fonet editor-in-chief Zoran Sekulic told CPJ.
Several SRS supporters surrounded Pavlovic, tried to take his camera, and then started punching and kicking him. Pavlovic was knocked to the ground several times, but eventually managed to escape to the safety of a nearby park.
CPJ was unable to confirm reports of attacks on journalists from the national BK Television network and Germany's ARD Television.
Two more journalists were attacked at a second rally held this evening in front of the Federal Parliament building in Belgrade, the Fonet news agency reported.
Two SRS supporters approached Reuters journalist Jelena Bozovic and asked for her affiliation. When Bozovic identified herself, they accused her of being a traitor on the payroll of foreigners. One of the men grabbed the reporter's arm and took away her notepad.
When Fonet journalist Zoran Culafic attempted to intervene, he was thrown to the ground and roughed up by several SRS supporters.
Fonet reported that a cordon of police officers standing nearby did not attempt to intervene.