Dallas: Dallas was gripped by a new security scare on Saturday triggered by an anonymous threat to police in the Texas city, on edge two days after a gunman fatally ambushed five police officers during a peaceful protest.

SWAT teams deployed around the headquarters of the Dallas Police Department while officers investigated reports of a suspicious individual in a parking garage — finally giving the all-clear around two hours later.

Dallas police tightened security throughout the city earlier Saturday after receiving an unspecified threat. The department said on Twitter that the search was conducted ‘out of an abundance of caution.’

‘The Dallas Police Department received an anonymous threat against law enforcement across the city and has taken precautionary measures,’ Dallas police said in a statement.

The scare came as another night of marches against police brutality got underway in several cities across the United States, a groundswell of protest that shows little sign of abating.

Protesters led by the Black Lives Matter movement have been demanding justice for two African-Americans who were fatally shot by police this week — their dying moments captured in viral video footage that stunned the nation.

The 25-year-old Dallas gunman, a black army veteran named Micah Johnson — killed in a showdown with police — told negotiators before he died that he wanted to murder white cops in revenge for the black deaths.

Dallas officials are now certain the atrocity was the work of a lone shooter and not a group of co-conspirators as initially feared.

But the nightmare scenes in Texas left many fearing a new, dark chapter in America’s troubled race relations.

President Barack Obama tried Saturday to reassure a shocked country, insisting that the United States can overcome its racial divisions, and rejecting comparisons with the civil unrest of the 1960s.

Obama, who will visit Dallas early next week, described the gunman as a lone wolf, a ‘demented individual’ who in no way represented the African-American community at large.

‘I firmly believe that America is not as divided as some have suggested,’ he said during a NATO summit in Warsaw. ‘There is sorrow, there is anger, there is confusion... but there is unity.’

‘Dangerous to be black’

The Black Lives Matter activist movement, which has spearheaded months of nationwide protests over police brutality towards African-Americans has demanded an end to violence — not an escalation.

Hundreds of people marched peacefully Saturday in New York for a third consecutive night, holding up banners bearing the names of Alton Sterling and Philando Castile, the two men whose deaths, in Louisiana and Minnesota, triggered the latest protests.

Other cities with marches planned on Saturday included Seattle, Indianapolis and Philadelphia — where organizers had called for a ‘Weekend of Rage.’

There were nasty scenes a night earlier 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 — weekend protests over the fatal shootings have passed off without trouble.

US politicians have sought to appear as unifiers after the week of violence.

‘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,’ said Newt Gingrich, a Republican former House speaker tipped as a possible White House running mate for Donald Trump. ‘Sometimes it’s difficult for whites to appreciate how real that is. It’s an everyday danger.’

Police on edge

There has also been a huge surge of sympathy for Dallas police after what marked the single biggest loss of life for law enforcement in the United States since the September 11, 2001 terror attacks.

Even before the new scare in Dallas, police were set on edge as it emerged that officers had been targeted in at least two other parts of the country — in Tennessee and Wisconsin — by individuals apparently angered at the recent fatal shootings.

Although the White House has ruled out any link between Johnson and known ‘terrorist organizations,’ his Facebook page ties him to radical black movements listed as hate groups.

Police found bomb-making materials and a weapons cache at his home and were scouring his journal and social media posts to understand what drove him to mass murder.