Protests turned violent in Minnesota, where several police officers were injured, one of them seriously. President Obama will travel to Dallas to comfort families and speak to the nation during a memorial Service.
More than 200 demonstrators were arrested during protests against the unprovoked police killings of black men in the US over the weekend.
The latest spasm of deadly violence began last week. Two police officers in Louisiana had seemingly subdued suspect Alton Sterling in a parking garage, when one of the officers pulled out his gun and fatally shot him.
One day later, another man, Philando Castile, was shot and killed by police during a traffic stop in Minnesota. Castile's death was live-streamed by his girlfriend who was sitting in the car next to him when he was fatally shot.
Content about both shootings quickly went viral on the internet.
A day later protests against the killings were organized across the country. As the demonstration in Dallas was ending, a black gunman perched inside a building opened fire on white police officers, killing five and wounding seven before being killed by a bomb-laden police robot.
It was the deadliest day for US police officers since the September 11 terrorist attacks in 2001.
Protesters attack police
A full-scale riot erupted on Sunday in St. Paul, Minnesota, which resulted in more than 102 arrests, according to police. Demonstrators blocked a highway and attacked police with rocks, bottles, fireworks, metal bars and Molotov cocktails.
The assault left 21 police officers injured - one of them seriously. Police spokesman Steve Linders said the officer was seriously injured after a 11-kilogram (25-pound) chunk of concrete was dropped on his head from an overpass.
In Baton Rouge, Louisiana where the other death occurred, one police officer was injured and more than 160 demonstrators were arrested in a series of protests, according to police.
Among those arrested was DeRay McKesson, a prominent figure with the Black Lives Matter movement. He was released on bond on Sunday.
"The only people that were violent last night were the Baton Rouge police department," McKesson told reporters outside the jailhouse. "The protesters remain peaceful both here and across the country."
Gun violence persists
The latest spasm of violence has shocked a country that is all too familiar with the epidemic of gun violence, injecting a new urgency into the national debate on race relations and how white police deal with black suspects.
"The best way to honor the memory of Alton Sterling, the Dallas law enforcement officers, and Philando Castile, is to protect the people here," Louisiana Governor John Bel Edwards said, referring to those killed in recent days.
President Barack Obama is due to visit Dallas on Tuesday to meet privately with the family members of the slain police officers. He will "personally express the nation's support and gratitude" for the officers' service and sacrifice.
The president will speak again during an interfaith memorial service, where he will be joined by Vice President Joe Biden and former President George W. Bush.
bik/rc (AP, Reuters, AFP)