Thousands of protesters are marching through the streets of Athens to mark the sixth anniversary of the fatal police shooting of an unarmed teenager, damaging store fronts and bus stations, and setting fire to clothes looted from a shop.

Clashes also broke out between demonstrators and police in the northern city of Thessaloniki.

No casualties were immediately reported.

In Athens, police say about 5,000 people are marching on Saturday night to commemorate the Dec. 6, 2008, killing of 15-year-old Alexandros Grigoropoulos in the capital.

The march passed the Greek Parliament, and is now heading to the spot where Grigoropoulos was killed.

At one point during the march, people broke into a Zara clothes shop in Athens, took racks of clothes into the street and burned them.