At least five officers were injured. One policeman was hit with a glass bottle and another by fireworks, according to St Paul police.
As she stepped out to play the US Open final on Saturday, Naomi Osaka wore a mask with the name Tamir Rice emblazoned on it.
Hundreds of people marched through Times Square in New York City to protest the deaths this week of Philando Castile and Alton.
Former champion Naomi Osaka is wearing a different facemask for each of her matches at the US Open this year.
Five officers were killed in a shooting in Dallas during a protest in response of the tragic deaths of Alton Sterling in Louisiana and Philando Castile in Minnesota.
Shocked family members demanded justice for Castile, a school cafeteria worker, whose mother described him as a law-abiding citizen who kept out of trouble.
The US president paid tributes to the five police officers killed in the deadly sniper attack in Dallas.
The best in international photojournalism was recently announced by World Press Photo's Annual Photo Contest. Despite fierce competition, the jury was forced to select just a handful of images from more than 73,044 photos by 4,548 photographers across 125 different countries. This year's grand prize was awarded to Venezuelan photographer Ronaldo Schemidt, earning him the title of Press Photographer of the Year. Here are some of the winners.