BRUSSELS - Belgian police detained more than 400 people on Saturday after “yellow vest” protesters inspired by riots in France threw rocks and firecrackers and damaged shops and cars as they tried to reach official buildings in Brussels. In the second violence of its kind in the capital in eight days, a crowd which police estimated at around 1,000 faced riot squads who used water cannon and tear gas to keep people away from the European Union headquarters and the nearby Belgian government quarter. Calm was restored after about five hours. The movement in Belgium, inspired by the “gilets jaunes”,...