Greek youths have clashed with riot police on the anniversary of the murder of a 15-year-old boy.

The 2008 shooting of Alexis Grigoropoulos sparked Greece's worst riots in decades and paralyzed Athens for weeks. Two policemen were convicted of the murder earlier this year.

Two years after his death, Greek police fired tear gas and percussion bombs at hundreds of young people throwing stones, flares, oranges and bottles during a march in Athens.

The youths also attacked local businesses, breaking windows, smashing bus stops and shooting red paint at the Bank of Greece, seen as a symbol of the country's unrest.

Riot police also skirmished with about 500 protesters in front of luxury hotels in Syntagma Square near parliament.

Police blocked traffic on main Athens avenues and squares, anticipating further protests.