After several days of intense rioting time is running out for Greece to enact unpopular austerity measures in order to prevent the country from going bankrupt.
Greece's Prime Minister, Lucas Papademos, has called for cooler heads as rioting and looting grip the city of Athens.
Sunday was seen as a critical time for Greece as a crucial parliamentary vote on austerity measures is debated to keep the country solvent and from falling off the euro.
Papademos in an address to the Greek people stated that vandalism and destruction "have no place in a democracy and will not be tolerated."
There were various reports describing a volatile scene including at least 15 businesses that were destroyed and dozens of shops looted throughout Athens.
The violence was due to a small fraction of the more than 100,000 overall demonstrators that were gathered outside of the parliament building.
Papademos spoke in parliament late Sunday before the vote on new austerity measures and said Greece should focus on the country's problems and not on rioting "at these crucial times."
Lawmakers on both sides have come under increasing pressure to resolve Greece's debt crisis. Tens of thousands of protesters collected in Syntagma Square in front of parliament in Athens.
Greece's government had warned that a rejection of the proposed measures would cause significantly worse conditions for Greeks.
In clashes with police protesters tossed homemade bombs made from gas canisters as riot police moved in on the crowds as they were firing tear gas and stun grenades.
Finance Minister Evangelos Venizelos explained to parliament that Greece had no easy solution and the other option to the international bailout, bankruptcy and a departure from the euro, would be far worse for Greeks.
"The choice is not between sacrifice and no sacrifices at all, but between sacrifices and unimaginably harsher ones," he said.
The austerity measures include pension cuts of $300 million euros and reducing the minimum wage about 750 euros a month.
The bill also will cut Greece's large state workforce by about 150,000 people by 2015.