Rising tensions from anti-austerity moves in Europe came to a head when thousands of protesters rioted at the opening of the new European Central Bank headquarters in Frankfurt, Germany.
Cars were set on fire and dozens of people were injured, including police officers.
Tensions have been high surrounding policies by the ECB, which is trying to revive Europe's sagging economy. A bailout plan for Greece has led to sharp exchanges between the Greek and German governments.
European Central Bank President Mario Draghi defended ECB policies at the opening ceremony, while protest organizers told Reuters reporters that Greece was being "asphyxiated" by belt-tightening austerity.
Click ahead to see scenes of the confrontations, and see more video coverage here.
—By CNBC's Anita Balakrishnan
Posted 18 March 2015
German police cars burn near the ECB building. The protest was organized by a group called Blockupy, named after the Occupy Wall Street movement in 2011, according to Reuters.
Blockupy says it represents grassroots critics of the ECB, the European Commission and the International Monetary Fund, whose inspectors monitor countries that have received bailouts.
A police officer stands next to a security barrier topped with barbed wire.
Despite protests, Draghi (center) cut the ceremonial tape as planned on the new 185 meter (600 foot) high skyscraper.
Activists march in a demonstration, while shops in downtown Frankfurt stayed shut.
Riot police form a cordon as a police car burns. Germany, the site of the protests, has been pushing the austerity measures as a way stabilize the EU's economy.
"The atmosphere is highly aggressive," police spokeswoman Tessa Koscheg said
The ECB, the European Commission and the International Monetary Fund together are known as the "troika" for their strict oversight of the $252 billion Greek bailout.
Anti-capitalist protesters rest in the central square in Frankfurt's old town. Police were able to clear the area around the ECB in time for Draghi's speech, while riots took place elsewhere in Frankfurt, reported CNBC's Annette Weisbach, live in Frankfurt.
A protester throws a stone during riots with police. Despite hundreds of arrests, Blockupy was still tweeting the start of big march through Frankfurt on Wednesday afternoon, U.S. time.
A German police officer who was hit by a paint bomb looks at a burning police car.