Protests have swept more than 10 cities across Greece -- a European Union member state with 11 million people.

Rows of riot police squared off with protesters for over an hour outside parliament before firing tear gas to disperse the crowd.

Bands of young protesters chanted: "Let parliament burn!"

Meanwhile, the funeral for Alexandros Grigoropoulos, a 15-year-old boy shot dead by police was carried out -- setting off clashes outside the cemetery.

The killing touched a raw nerve among young Greeks, angry at years of political scandals and rising levels of poverty and unemployment. A situation -- that has been worsened by the global economic downturn.

Prime Minister Costas Karamanlis is keeping the president updated and says the government will deal firmly with acts of violence.

Police say that in Athens alone, rioters damaged or destroyed 200 stores and 50 banks overnight. The continuing violence has dashed retailers' hopes that Christmas would compensate for Greece's darkening economic outlook.