Serbian police have fired tear gas at anti-government protesters in downtown Belgrade as they clashed for the third day on the streets of the country's capital and other cities amid reports of police brutality and excessive use of force during the unrest.

Serbia's police used teargas and crowd control vehicles on Friday evening in Belgrade to disperse anti-government protesters who threw firecrackers and flares at police officers in what is seen as a major escalation of the nine-month-long protests.

The unrest in Belgrade and throughout the country marked a serious escalation of more than nine months of largely peaceful demonstrations led by Serbia's university students that have shaken Vucic's firm grip on power.