(CNN)A flash mob in Germany turned violent on Saturday as teenagers attacked and threw stones at police officers, authorities said.
About 600 youths gathered in Frankfurt on Saturday evening, before running up and down a popular shopping street "without taking any account of passers-by," police said in a statement.
A 17-year-old then punched a police officer as he attempted to issue the flash mob's organizer with a dispersal notice, causing the officer to be injured. As the teenager was arrested, other attendees began throwing stones at the officers.
"Due to his resistance, the teenager had to be brought to the ground. He suffered a minor injury, which was immediately treated on an outpatient medical basis," police claimed.
They added that two male and one female police officers were hit by stones, with one being hit on the head.
Investigations have now begun into those responsible for the flash mob, and whether they will have to pay for damages incurred.
The event was being staged by two separate YouTubers and their fans, police added on Twitter.
It follows similar scenes in Berlin on Thursday, when fans at an event organizer by another YouTuber were arrested.