Small-scale attacks continued across Greece on Wednesday as protesters angry with the fatal police shooting of a teenager in Athens called for mass demonstrations across Europe.

A group of about 10 protesters hung two giant banners over the walls of the Acropolis, one bearing the word "Resistance" in Greek, English, Italian and German.

The other banner called for mass demonstrations across Europe on Thursday, a day students are planning to protest in Athens and Greece's second-largest city, Thessaloniki.

The two cities had some incidents of violence on Wednesday. Youths threw petrol bombs at a riot police bus in central Athens, police said. The driver managed to escape unharmed but the vehicle was damaged.

About 100 high school students gathered outside the Athens court complex, pelting riot police guarding the building with stones, eggs, rocks and yogurt to demand that those detained in the riots be freed.

In Thessaloniki, police said a bank and a local citizens advice office were firebombed before dawn Wednesday. No one was injured in the attacks.

Despite the attacks, the rioting has subsided since the violent protests were sparked by the Dec. 6 police killing of 15-year-old Alexandros Grigoropoulos.

More than 300 people have been detained or arrested as masked and hooded youths have marched through the cities, smashing, torching or looting buildings and clashing with riot police.