BERLIN (AP) -- German police say they allowed an anti-Israel protester to use a megaphone in a police car during a "Free Gaza" demonstration in Frankfurt and he shouted inciting slogans including "child murderer Israel" and "Allahu akbar."

Frankfurt police spokeswoman Virginie Wegner said Sunday they let the protester use the megaphone because the demonstration had turned violent and he had offered them to calm down the situation.

But instead of doing that, he shouted anti-Israel slogans. A video shows a crowd following the police car during Saturday's protest and repeating the chants blaring over the megaphone, which also included "Free Gaza."

It wasn't immediately clear if police would launch an investigation into the incident, but Wegner said police are neutral during protests.