After pointing out a possible rampage announcement on the Internet, the police arrested a man in Leipzig on Thursday.

Forces of the special task force and the Leipzig police department secured the 21-year-old in an apartment in the south of the city, as a police spokesman confirmed in the morning.

The social network Snapchat informed the American authorities because a user’s video indicated a possible act of violence in a school. As part of international cooperation, the tips ended up at the Leipzig police department via the state and federal criminal police.