BERLIN (AP) — Police in Germany used water cannons and pepper spray against protesters after a demonstration organized by far-right groups in the western city of Cologne turned violent Sunday.

A spokesman for the city's police said officers in riot gear were deployed to calm the situation after protesters threw bottles, stones and fireworks at them.

A police vehicle was also overturned by protesters.

Thirteen officers and one protester were injured in the clashes, said police spokesman Andre Fassbender. Six people were detained, but further arrests would likely follow a review of video footage, he said.

Some 2,000 people had massed in the heart of Cologne's historic center for a demonstration ostensibly aimed against Islamic extremism. It was organized by neo-Nazi groups and members of Germany's football hooligan scene.

German news agency dpa reported that some protesters were heard chanting "foreigners out."