Police in riot gear contained around 200 protestors who poured out on the streets of Ferguson, Missouri, to mark the anniversary of the police shooting of Michael Brown, an unarmed teen whose death ignited racial tension.

Once again, the St. Louis suburb was declared a state of emergency. At least 12 people were arrested late on Monday, though demonstrations were in most part peaceful at first. A cat and mouse game esnued over the course of the night as police in riot gear staged raids on a group of 1,500 people resulting in more than 50 arrests as demonstrators blocked traffic with barricades.