STANDING halfway up the Art Museum's steps, Andre Hawkins waved an American flag with all its traditional colors stripped away, its stars and bars all black and white.

About a thousand people stood beneath and above him as the BlackOut Philly demonstration began to unwind last night. Many of them held signs and kept chanting, while others huddled in their own groups, decrying alleged acts of injustice in both Philly and elsewhere in America.

"It's not about red, white and blue, or black and white," Hawkins, 24, said of his flag. "It's about certain people killing other people."

Shortly after 10 p.m., police said protesters were still out and some were attempting to block traffic on the Vine Street Expressway.

For the vast majority of last night's protesters, that meant police officers killing unarmed black men.

"No justice. No Peace. No racist police," protesters chanted as the crowd made its way through around City Hall and through Center City.

The BlackOut Philly protest, organized by West Philly resident Raheem Harvey, started at about 7 p.m., an hour after a candlelight vigil began in Brooklyn for two police officers shot dead in their patrol car Saturday by a gunman who claimed he sought to avenge the death of Eric Garner.

Many of last night's protesters wore "I can't breathe" T-shirts and hats in honor of Garner and street vendors were following the crowd, selling shirts for $10 and winter hats for $5.

Though no one with a bullhorn appeared to address the deaths of the NYPD officers, Justin D. Barker, 24, of North Philly, said no one is calling for violence against police.

"The issue is the system, not good police," he said. "It's a terrible shame what happened there."

Police Commissioner Charles Ramsey, tapped by President Obama earlier this month to lead his Task Force on 21st-Century Policing in the wake of riots in Ferguson - in an interview with NBC Nightly News last night - blamed "heated rhetoric" in part for the killings of the two New York officers.

"Right now, I think everyone just needs to take a deep breath, step back a bit and slow down on the heated rhetoric," Ramsey said. "I think that's part of the issue that led to this, quite frankly, so we need to really have thoughtful discussion . . . going to extremes in terms of the rhetoric is not helpful at all."

The family of Brandon Tate-Brown, who was shot and killed on Dec. 15 in Mayfair, was among the crowd on the art museum steps, wiping away tears and warming their hands.

"His life matters," a small crowd shouted around Brown's mother.

Police said Tate-Brown, 26, went for a gun and killed him. Tate-Brown's mother, Tanya, said she buries him today.