Protesters are promising to remain on the streets of Greece, one week after the police killing of a 15-year-old boy sparked massive riots. Demonstrations are scheduled Saturday, followed by daily rallies over the next week, including plans to gather outside police headquarters. Riots that followed the police shooting of 15-year-old Alexandros Grigoropoulos have left hundreds of stores smashed and looted. At least 70 people have been injured and more than 200 arrested. The protests are driven in part by the widening gap between rich and poor in a country where the minimum monthly wage is â‚¬658 ($850), graduates have poor job prospects and the government is making painful reforms to the pension system. "It is clear that this wave of discontent will not die down. This rage is spreading because the underlying causes remain," said veteran left-wing politician Leonidas Kyrkos. At the site where Grigoropoulos was shot, scores of people came to leave flowers and pin messages to a notice board. A privately made street sign was placed on the corner of the block with the teenager's name. Internet tribute sites were also flooded with messages. "We want a better world. We are not hooligans or terrorists ... we are your children. You were young once too." wrote "Theo" on one of several groups dedicated to the dead teenager on Internet networking site Facebook. Beleaguered Prime Minister Costas Karamanlis on Friday ruled out early elections, and renewed calls on opposition parties to issue stronger public condemnations of the violence. "We must make a very clear distinction between the overwhelming majority of the Greek people who of course have every right to express their sorrow at the death of a young boy, and the minority of extremists who take refuge in acts of extreme violence." he said. Athens Mayor Nikitas Kaklamanis renewed calls for demonstrations to remain peaceful and promised to replace the city's torched Christmas tree next week. "Those people who caused damage don't love this city," Kaklamanis said. "I'm asking for everyone to come to join the Christmas celebrations, as an answer to these people ... Athens will get back on its feet." Christmas shoppers cautiously returned to central Athens Saturday, with many shops boarding up their windows instead of replacing glass for fear of further violence. Glazier Michalis Mentis said he had replaced several storefronts twice. "There's been a lot of work for us but it's very bad for businesses in general," Mentis said. "It's very lucky more people were not hurt, because there was so much damage."