Youths protested outside of Athens' main police headquarters on Monday, pelting riot police with flour and other objects to protest the shooting death of a teenager. Riot police responded with tear gas.
Some 2,000 youths at the rally blocked one of the capital's main avenues, chanted slogans and set fire to trash bins before dispersing. Two demonstrators were arrested.
Students also staged peaceful blockades of several other busy roads Monday in the capital and protested outside Athens' main court complex, where five people arrested during last week's riots were to appear before an examining magistrate. Riot police guarded the complex and no disturbances were reported.
Greece has seen its worst riots in decades after 15-year-old Alexandros Grigoropoulos died Dec. 6 in a police shooting. The riots quickly spread from Athens to more than a dozen cities. For a week, youths smashed and burned stores and cars, and hurled petrol bombs and rocks at riot police, who responded with stun grenades and large amounts of tear gas.
Dozens of people were injured in the rioting, while hundreds of stores were damaged or looted and more than 200 people were arrested. The policeman accused of killing the teenager has been charged with murder and is being held pending trial.
However, the protests are shifting from just expressing anger at police to showing general anger at the country's increasingly unpopular conservative government and the economic hardships faced by many Greeks.
Socialist opposition leader George Papandreou renewed calls Monday for early elections.
"The government cannot deal with this crisis," he said. "It cannot protect people _ their rights or property _ and it cannot identify with the anxiety felt by the younger generation."
Prime Minister Costas Karamanlis, whose party has only a single seat majority in parliament, has repeatedly rejected calls to resign and call early elections, saying the country needed a steady hand in times of crisis.
Sunday was the first trouble-free day since Grigoropoulos' killing, but some groups, mostly left-wing students, have vowed to keep up the protests until the government addresses their concerns.
Protesters have called for riot police to be pulled off the streets, for police to be disarmed and for growing social inequality to be resolved.