Violent protests

Athens police on Sunday used tear gas to disperse crowds damaging store fronts and setting fire to trash cans.

Hundreds of hooded youths broke from the anniversary march commemorating the death of 15-year-old Alexis Grigoropoulos who was shot dead by a policeman last year.

Four police officers and two demonstrators were injured in Sunday's clashes, and 80 people were detained, police said.

Violence also erupted in the northern city of Thessaloniki, where youths threw petrol bombs at police, set several cars on fire and smashed store windows. At least 20 people were detained in Greece's second largest city.

Around 500 people participated in protest marches in the northern city of Thessaloniki on Saturday night. Students occupied dozens of universities and schools to commemorate the teenager's killing, according to staff unions.

Weekend raids

Police already detained more than 150 people in several raids in Athens on Saturday night.

Two cars were set alight in the Athens district of Exarchia, where the killing of 15-year-old Alexis Grigoropoulos on December 6 last year sparked serious violence in the weeks that followed.

Police sources said that twelve people, including Italians and Albanians, were arrested over the car attacks while another 81 people were taken in from nearby to help with questioning.

Riot police also stormed an occupied town hall in the western Keratsini district, detaining 41 people.

In a separate raid on a suspected anarchist hideout nearby, police rounded up 20 people. On the premises officers found two gasoline canisters, sledgehammers, gas masks, a stun grenade and bottles. As police were searching the house, they said they were attacked by about 60 youths with rocks.

"The search confirmed prior information that this location was used to create explosives and launch attacks," said a police statement.

Two police officers were injured and taken to the hospital on Friday after clashes with protestors.

Zero-tolerance approach

The Greek government had deployed thousands of extra officers in anticipation of the protests.

Police said they would implement a "zero-tolerance attitude" to the demonstrations, after damages caused by last year's riots amounted to millions of euros.

Grigoropoulos was shot dead by an officer who claimed he fired into the air when youths attacked him. The policeman is due to go on trial on January 20, charged with homicide.

nk/rc/AFP/Reuters/AP/dpa

Editor: Kyle James