Berlin police said today that nine participants had to be treated for breathing difficulties at the meeting Sunday night which was about Iraq's semi-autonomous Kurdish region decision to hold a referendum on independence next month.
The Turkish government is strictly opposed to such a vote and has warned that a referendum could lead to civil war.
Turkey is also involved in a long-simmering conflict with Kurds for more independence in its own southeastern region.
Police said it wasn't clear who was behind the incident in Berlin which was attended by 400 people.