"What started as an outburst of rage over Alexandros' killing is now becoming a more organized form of protest," said Petros Constantinou, an organizer with the Socialist Workers Party.
Protesters began handing out fliers listing their demands, which include having riot police pulled from the streets and the reversal of public spending cuts that have heightened insecurity over jobs.
The demonstrators have also begun adopting opposition demands for more financial relief for low-income Greeks. Greece's minimum wage is euro658 ($850) per month.
The broadening discontent spells trouble for conservative Prime Minister Costas Karamanlis' government, which has just only a one-seat majority in parliament. Even before the worst rioting in decades, his popularity was suffering amid financial scandals and unpopular economic and social reforms.
"We demand accountability, that this government resigns, and that this farce comes to an end," said 28-year-old Spyros Potamias, an architecture student at the Athens Polytechnic, where rioters have hunkered down and taken advantage of Greek law forbidding police from entering campuses.
Opposition parties are demanding Karamanlis resign and call early elections, arguing that his policies generated a social crisis that fueled riots and that police left Greece's cities defenseless.
Analysts said there had been warning signs of deepening social discontent.
"It was to be expected that an incident like the (boy's death) would produce a response of much greater intensity than at another point in time," said Dimitris Mavros, director of the market research firm MRB Hellas. "There were indicators of this (problem) before these events occurred."
He cited an MRB tracking poll released in June, which concluded that three-fourths of the 2,100 Greeks polled believed that "things are going badly."
"That's the worst level since 1987," Mavros said. The poll had a 2 percentage point margin of error.
Protests have spread beyond Greece's borders, with demonstrations in several European countries, including Italy, Spain and Denmark. Greek diplomatic missions have been vandalized in Istanbul and New York.
But after five days of mayhem, Greece slowed down Thursday to breathe. People ventured out into the streets; shops reopened in central Athens, many serving customers behind smashed storefronts covered with boards or garbage bags.
Even the students seemed more relaxed, agreeing to speak to reporters without having their faces uncovered. One protester, Constantinos Sakkas, spoke politely in English and said the students are now trying to encourage nonviolent action in Greece and abroad.
"This is about our future," Sakkas said.
