A St. Louis resident wants the Bosnian flag to be the next flag to fly at City Hall, to commemorate the 21st anniversary of the Srebrenica massacre in July.

John Hadley, 18, started a petition Saturday asking people to support his effort to fly the Eastern European country’s flag at City Hall. The number of signatures on the petition surpassed 200 names on Wednesday. Hadley’s new goal is to reach 500 supporters. He says he plans to email the petition to Mayor Francis Slay.

The petition calls for the flag to fly July 11-22 to commemorate the anniversary of the mass killing of more than 8,000 Muslim men and boys by the Bosnian Serb army in Srebrenica during the Bosnian War over two decades ago. Tens of thousands of Bosnians live in St. Louis, making it one of the largest concentrations of Bosnian residents outside of Europe.