Fifteen people were arrested overnight in Ferguson after taking part in protests against a decision not to indict the white police officer who killed an unarmed black teenager.
Tensions escalated after police said protesters began illegally blocking an avenue.
A group of around 100 protesters had marched down the avenue towards the city's police and fire departments chanting, blocking traffic and stopping in front of businesses. One protester said:
I served my country. I spent four years in the Army, and I feel like that's not what I served my country for. I served my country for justice for everyone. Not because of what colour, what age, what gender or anything.
Armies of protesters took to the streets following the Ferguson shooting decision, in a sign of the monumental challenge now facing America.
The police officer who shot dead Michael Brown says he has a clear conscience over his actions.