ATHENS, Greece - Athens was calm Sunday after eight days of the worst riots Greece has seen in decades, sparked by the police killing of a teenager.

Traffic returned to normal in the center of town and an open-topped double-decker bus carried tourists round the city's main sights. The popular cafes in the Thissio area under the Acropolis were busy, and couples took their young children for a Sunday walk.

But Greek youths who have protested daily since the boy's death have vowed to remain on the streets until their concerns are addressed. Protesters are angry not just at the police but at an increasingly unpopular government and over economic issues.

A newspaper poll published Sunday showed the governing conservatives' popularity at a dismal 20.6 per cent, 5.6 percent below the main opposition Socialists. However, 55 per cent of respondents said neither party seemed competent to handle the situation.

The Focus poll of 1,000 people for Real News gave a 3.1 per cent margin of error.

Violence has wracked Greece every day since the death of 15-year-old Alexandros Grigoropoulos, spreading quickly from Athens to more than a dozen other cities and leaving at least 70 people injured. Hundreds of stores have been smashed and looted, and more than 200 people arrested.

Late Saturday and early Sunday, youths in Athens attacked a police station, stores and banks and fought running battles with police, as candlelit vigils were held to mark a week since the shooting.

A new candlelit vigil is planned for Sunday evening at the site of the shooting. A separate protest is scheduled in western Athens.

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 those fringe elements than in the past.

"In the end, the violence that we use is minimal in comparison to the violence the system uses, like the banks," said 32-year-old protester Paris Kyriakides. "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."

In a poll released Sunday, some 62 per cent of respondents said the reactions to the shooting were inexcusable, compared with 35 percent who believed the violence was justified. The poll of 1,000 people gave no margin of error.

According to another poll, Greeks see more in the violence than a simple reaction to the shooting.

Asked whether the riots were a social uprising, 60 per cent responded yes. Some 64 per cent considered police were unprepared for the violence.

The poll of 520 people published in the Kathimerini newspaper gave a 4.5 per cent margin of error.