University and high school students mobilized in central Athens on Friday for a rally while students occupied more than 400 school buildings across the country, reported dpa.
Hundreds of stores have been burned or gutted since riots began last Saturday as gangs of hooded youths and self-styled anarchists smashed windows, looted shops and set up flaming barricades in streets across the country.
Students and teachers called the demonstration to protest the police shooting of a teenager but also growing corruption and economic and education reforms.
On Friday, dozens of students occupied the airwaves of radio station Flash for more than an hour, cutting programming to state their grievances against lying politicians, multinationals and journalists.
"We are against the government and the growing power by the police who believe that they can shoot whenever and whomever they want," said Mario Bakiari, the president of the student body of the Athens district of Peristeri.
"There is no way that the government can justify banks a 28- million-euro bail-out plan yet no money towards the educational system. Classes are without heating and many times are held in portables."
The riots have spread beyond Greece's border, hitting other European countries. Angry youths have reportedly also smashed shops, attacked banks and damaged police vehicles in Spain, France and Denmark.
Despite the intensity of the protests which have rocked the country for six consecutive days, public criticism over Prime Minister Costas Karamanlis and his ruling conservative government's aloofness to the civil unrest increased.
"The Bell Tolls for Karamanlis," the headline of the top-selling daily Ta Nea newspaper read.
The government, which has seen its popularity ratings fall sharply behind the opposition Socialists in recent months, promised once again to compensate businesses for the millions of euros of damage suffered - announcing loans, emergency subsidies and tax relief measures.
Store owners, which have suffered millions in damage, accused authorities of leaving their businesses unprotected as rioters smashed and burned their way through popular shopping districts. Although police have responded when attacked by firebombs, they held back when youths turned their rage against buildings and cars.
"During one of the riots dozens of workers were trapped inside as hooded youths started to smash the windows," said Dimitra Anastasiadou of Zorpis Travel, which is located across the road from Athens University.
"We called police for help but they told us there was nothing that they could do and told us to protect ourselves."
The shooting of 15-year-old Alexandros Grigoropoulos by police on Saturday sparked days of rioting across the country.
A ballistics report into the shooting was due to be made public later Friday.
The State Secretary for Police, Panayiotis Hinofotis announced possible new measures for the Greek police force on Friday, which include determining which officers should be entitled to carry weapons and annual psychological tests.
All police in the Greek force have the right to carry loaded guns.