THESSALONIKI, Greece (AP) — Greek police fired tear gas Monday to disperse youths attacking them with firebombs and stones in the northern city of Thessaloniki at a march marking the 13th anniversary of the fatal police shooting of a teenager.

No arrests or injuries were reported after the clashes, which did not last long. They followed an otherwise peaceful march by about 6,000 people.

The 2008 killing of the 15-year old boy in Athens triggered weeks of the worst riots the Greek capital had seen in decades, with extensive destruction of shops and other private and public property, looting and street fights with police.

Two police officers were jailed in connection with the killing, which followed an altercation between a group of youths and one of the officers.

Several thousand people also staged a protest march in Athens late Monday, which ended peacefully. Minor clashes ensued when youths threw stones at police. Earlier, a midday march in the Greek capital by schoolchildren and university students ended without incident.