Hundreds of students took to the streets of Athens on Thursday to take part in a rally commemorating the 10th anniversary of the killing of 15-year-old Alexis Grigoropoulos, who was murdered by a policeman in 2008.

Protests escalated when men wearing masks separated from the main group to destroy street furniture and throw stones at public buildings, forcing the Greek capital's downtown area to shut down.

"We haven't had the last word yet. These days are dedicated to Alexis," read a banner held up by demonstrators.

Police responded by attempting to disperse the crowds using tear gas.

At least 10 people were arrested, one of them with a slight injury to the head, police sources told EFE.

On the night of Dec. 6, 2008, a police officer belonging to the so-called Special Guards unit named Epaminondas Korkoneas fired his service revolver at a group of youths in Athens' bohemian Exarcheia neighborhood after a verbal dispute, killing Grigoropoulos.

The homicide sparked mass protests and violent riots throughout the country that lasted for three weeks before subsiding.

In 2010, Korkoneas was sentenced to life in prison and his partner, Vasilis Saraliotis (who was present during the shooting), was handed 10 years in jail after being found guilty as an accomplice.