Scores of youths attacked a police station, stores and banks, as candlelit vigils were being held to mark a week since the police killing of a 15-year-old boy that triggered massive riots across Greece.

PHOTOS: Bombs rain in Athens

Dozens of youths on foot and on motorcycles attacked a police station in central Athens on Saturday, at least three banks, several stores and a government building, authorities said.

The youths threw at least one petrol bomb at the police station on Saturday evening before smashing paving stones and setting up barricades with burning trash bins.

The latest violence occurred as hundreds of school children holding candles gathered peacefully outside parliament and at the site where teenager Alexandros Grigoropoulos was shot.

Violent protests have injured at least 70 people and left hundreds of stores smashed and looted in Greek cities over the past week. More than 200 people have been arrested.

While most of the protesters have been peaceful, the tone of the demonstrations has been set by a violent fringe. And more young people have been willing to join them than in the past.

Outside parliament, hundreds of school children sat in silence. Candles spelling out the name "Alex" were left in front of a line of riot policemen.

Greek youths taking part in protests every day since the boy's death are angry not just at the police but at an increasingly unpopular government and over economic issues.

The young protesters promised to remain on the streets until their concerns are addressed.

"Speaking as an anarchist, we want to create those social conditions that will generate more uprisings and to get more people out in the streets to demand their rights," said 32-year-old protester Paris Kyriakides.

"In the end, the violence that we use is minimal in comparison to the violence the system uses, like the banks," Kyriakides said.

Earlier on Saturday, a crowd of about 1,000 people attended a peaceful sit-down demonstration in Athens and another 1,000 demonstrated in the northern city of Thessaloniki.

One 16-year-old student at the Athens demonstration, who gave only her first name, Veatriki, said young people her age felt their voices were being heard immediately when they smashed a shop window or a car.

She also said young people want to see the policemen involved in the shooting punished and the police disarmed.

The two officers involved in the boy's shooting were arrested. One was charged with murder and the other as an accomplice. The circumstances surrounding the shooting are unclear.

Giorgos Kyrtsos, publisher of the City Press and Free Sunday newspapers, said the violent demonstrations revealed widespread signs of public discontent.

"We are entering a long period of economic crisis," Kyrtsos said. "But there is also a deepening social crisis, combined with a weakened state. We are truly at a crossroads."

Kyrtsos, a conservative, was highly critical of the government's handling of the protests.

"This is the only government I remember that has managed to alienate both the rebellious youth and the law-and-order crowd," he said. "It has nothing to offer to anybody."

Christmas shoppers cautiously returned to central Athens on Saturday, but many stores boarded up their windows instead of replacing the glass, for fear of further violence.

Athens Mayor Nikitas Kaklamanis greeted shoppers with the city's brass band.

"People came up to me and were telling me that it was the first time they had smiled in days," the mayor said