BERLIN (AP) — Berlin police said Wednesday they are investigating an attack on a conference room being set up for the far-right Alternative for Germany party, which blamed it on far-left “antifa” protesters.

The attack came Tuesday afternoon after two women who had made an appointment to tour the facility in the eastern neighborhood of Kaulsdorf were let inside, police said.

They then opened the doors to allow 10 to 15 masked people to storm inside, where they threw chairs and scattered confetti around the conference room being prepared for a meeting of AfD's Berlin branch.

They fled as police arrived, and police said they had no immediate suspects.

AfD said in a statement that the attackers were part of the anti-fascist "antifa” movement and had threatened more action in the coming days.

Germany's antifa movement emerged in response to the resurgence of Nazi ideology in the country. It has no central structure, but instead represents a widespread stance among left-wing and far-left groups that combating fascism involves hands-on activism, some of which has resulted in violence.