Police in Greece have clashed with Communist-backed demonstrators who tried to prevent a concert by U.S. military cadets.

According to Kathimerini (through AP), the violent protest occurred in the central Greek city of Larissa.

Members of the West Point Glee Club, a musical group of the U.S. Military Academy, is currently on tour in Greece and was scheduled to perform in the city.

Videos and photos shared on social media show police firing tear gas to hold back the demonstrators outside a municipal theatre, while officers also clashed with a smaller number of protesters as they entered the building.

Reports say it was not immediately clear if the concert took place while authorities and the venue couldn’t be reached for comment.

There were no reports of arrests or injuries.

Protest organisers from the Greek Communist Party oppose the presence of U.S. troops in Greece as well as Greek military support for Ukraine and involvement in international maritime security missions in the Red Sea.