Riot police in Athens used tear gas Monday to repel rock-throwing protesters near the Greek Interior Ministry and parliament. The demonstrations were sparked by the fatal police shooting of an Athens teenager on Saturday.
The new fighting erupted as Greek Prime Minister Costas Karamanlis vowed to end "dangerous" rioting that has spread across the country since the killing. Authorities describe the rioting as the worst to hit Greece in decades.
Mr. Karamanlis, speaking on national television, said the rioting will not be tolerated. He said the government "will protect society."
Hundreds of protesters also clashed with police in the northern city of Salonika. And at least one police officer was injured in Trikala.
Protesters in London scuffled with police outside the Greek embassy, tearing down the Greek flag and raising an anarchist banner. Separately, 15 protesters occupied the Greek consulate in Berlin for a number of hours before leaving peacefully.
Authorities in Athens are bracing for wider protests Wednesday as labor groups plan a 24-hour general strike against government economic policies.
The violence began Saturday in the Greek capital after police gunfire killed a teenager. The two police officers involved have been arrested and charged - one with premeditated murder and the other as an accomplice.
The officers said their patrol car came under attack and that they responded with warning shots. However, witnesses said one of the officers aimed his weapon at the 15-year-old boy, and fired.
Some information for this report was provided by AP and Reuters.