President Barack Obama assured a shocked America on Saturday that the black army vet who shot dead five cops in Dallas was a lone wolf -- and that the country can overcome its racial divisions, as the groundswell of anger over police brutality surged on.
Fresh protests were planned in at least half a dozen cities to demand justice for two African-Americans whose fatal shooting by police triggered the Dallas rampage of an angry radical bent on revenge.
The nightmare scenes in Texas, where a peaceful protest turned to horror, left many fearing a new, dark chapter in America's troubled race relations.
But as Dallas honoured its slain officers, Obama sought to cut short that narrative.
"I firmly believe that America is not as divided as some have suggested," he told a news conference at a NATO summit in Warsaw. "There is sorrow, there is anger, there is confusion... but there is unity."
Obama described the 25-year-old gunman, Micah Johnson, as a "demented individual" who in no way represented the African-American community at large.
Dallas officials say they are now certain the atrocity was the work of a lone shooter -- killed in a showdown with police -- and not a group of co-conspirators as initially feared.
At Dallas police headquarters, people flocked to leave flowers and messages of sympathy for the slain officers amid an outpouring of support that saw crowds in the city line up to hug police officers.
After visiting the memorial Saturday, Mayor Mike Rawlings voiced hope that the shock from the killings could serve a purpose "in a grander plan to make us a stronger country, a stronger city, and a stronger world."
'Dangerous to be black'
The Black Lives Matter activist movement, which has spearheaded months of nationwide protests over police brutality, has demanded an end to the violence -- not an escalation.
As thousands marched in US cities overnight, there were nasty scenes in Phoenix, Arizona, where police used pepper spray to disperse stone-throwing protesters. And in Rochester, New York, 74 people were arrested over a sit-in protest.
But elsewhere -- from Atlanta to Houston, New Orleans, Detroit and Baltimore -- protests held over the fatal shootings of Alton Sterling in Louisiana and Philando Castile in Minnesota passed off without trouble.
Cities expecting new gatherings on Saturday included Seattle, Indianapolis and Philadelphia -- where organizers called for a "Weekend of Rage."
Obama is to visit Dallas early next week in the effort to chart a way forward, while a raft of US politicians sought to appear as unifiers after a week of violence graphically highlighted America's racial challenges.
"White Americans need to do a better job of listening when African Americans talk about the barriers they face," Democratic White House hopeful Hillary Clinton tweeted.
That message was echoed by prominent members of the Republican Party, which has often jumped to defend law enforcement amid accusations of racial bias.
"It is more dangerous to be black in America," Newt Gingrich, a Republican former House speaker tipped as a possible White House running mate for Donald Trump, said in an interview on Facebook Live.
"Sometimes it's difficult for whites to appreciate how real that is. It's an everyday danger."
Republican Florida senator Marco Rubio had a similar message. "Those of us who are not African American will never fully understand the experience of being black in America," he said.
Trump himself put out a video statement, seated presidential-style behind a large desk, in which he acknowledged the Louisiana and Minnesota shootings and spoke of "how much work we have to do in order to make every American feel that their safety is protected."
Police on edge
The Dallas ambush marked the single biggest loss of life for law enforcement in the United States since the September 11, 2001 terror attacks.
Police were set further on edge as it emerged that several officers had been targeted across the country by individuals apparently angered at the recent fatal shootings.
In Bristol, Tennessee, a man opened fire Thursday on a hotel, killing a woman, wounding several others and grazing a police officer with a bullet.
The Tennessee Bureau of Investigation said the gunman "may have targeted individuals and officers after being troubled by recent incidents involving African-Americans and law enforcement officers."
And in Racine, Wisconsin, police said a 43-year-old man was arrested over threatening social media posts that read: "I encourage every Black man in America to strap up... I encourage every white officer to kiss there (sic) love ones goodbye."