Violent demonstrations broke out in multiple Swiss cities, where American flags were set ablaze and riot police confronted protesters before President Trump’s arrival in Davos for the World Economic Forum.

Trump is set to arrive on Wednesday and is anticipated to give an address at the yearly assembly of international political figures and business leaders.

His visit follows Trump’s reinforced effort to obtain Greenland for U.S. national security purposes and his refusal to dismiss potential military action.

The Davos forum, located in eastern Switzerland, ranks among the globe’s most prominent economic conferences, convening state leaders, CEOs, financiers, and policymakers to deliberate on worldwide trade, security, and geopolitical issues.

Approximately 300 protesters walked through Davos on January 19 to voice opposition to both the forum and Trump’s scheduled participation.

Chanting and carrying signs that said “Trump not welcome,” the demonstrators charged Swiss authorities with normalizing what they called a controversial figure by welcoming the U.S. president.

Pictures from the events depicted masked protesters burning American flags, and local news accounts noted broken windows and additional damage to property.

A Swiss outlet reported that clashes began after protesters confronted police lines.

Police in full riot equipment used water cannons, chemical agents, and rubber bullets, stating they had fireworks launched at them.

The outlet further cited a police report stating “paint bags were thrown at building fronts and shop windows were shattered at the intersection of Bahnhofstrasse and Uraniastrasse,” with the total extent of the damage not yet determined.

Two officers were also said to have been struck by stones but were not injured.

Comparable protests occurred in other locations, such as Bern, where police dispersed a demonstration after cordoning off the downtown area.

In Zurich, thousands participated in a march on Sunday evening, with one sign stating, “Put the Trumpster in the dumpster.”

Members of the Swiss NGO Campax also beamed a large image of Trump onto a ski slope near Davos, labeling him the “Spirit of plutocracy.”

Economic policies are predicted to be a central topic of conversation at the summit, along with discussions on the Ukraine war and wider international security issues.

Trump reiterated his stance in a social media post early Tuesday.

“As I expressed to everyone, very plainly, Greenland is imperative for our strategic future,” Trump wrote. “There can be no going back — on that, everyone agrees. The United States of America is the most powerful country anywhere on the globe, by far.”