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. 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.