Greek protesters burned buildings, smashed windows and pelted police with rocks and gasoline bombs Sunday while parliament debated more spending cuts demanded by international lenders.

Police say around 100,000 protesters marched through Athens and the second largest city, Thessaloniki.

At least 10 buildings in Athens were set on fire, including movie theaters, cafes and banks.

Police attacked the rioters with tear gas.

The marchers ranged from young men with masks and shaved heads to families and the elderly. Many Greeks say they already have sacrificed enough as the government strives to emerge from its huge debt and avoid bankruptcy.

The Greek Cabinet approved a new austerity package on Friday. Thousands of jobs would be eliminated, the minimum wage would be cut, and the pension system would be reformed.

If parliament passes the measure, the European Union and International Monetary Fund likely would give final approval to a $172 billion bailout loan so that Greece can head off bankruptcy.

Prime Minister Lucas Papademos warns of social and economic catastrophe if lawmakers reject the measure.

Greece faces bankruptcy if it is not able to pay investors $19 billion in debt when government bonds come due next month. The government is negotiating a bond swap with the creditors that would save the country billions of dollars.