I was walking past Freedom Plaza on Pennsylvania Avenue in Washington on Tuesday afternoon and saw a group of people were staging a die-in. The two dozen young men and women, of all races, were protesting the Monday night grand jury decision in Ferguson, Missouri, not to indict Darren Wilson, a white police officer who fatally shot black teenager Michael Brown in August.

On Tuesday evening, angry protesters in Washington also burned a US flag outside the American Portrait Gallery near Chinatown. Such were just two of the many protests and some riots that have taken place in many US cities in the last two days. Protests have actually never stopped in Ferguson in the 110 days since 18-year-old Brown was shot six times on Aug 9.

The deployment of thousands of National Guard members, the use of tear gas and the hundreds of arrests made by the police also show how tense the relationship is between protesters and law enforcement.