WASHINGTON: "Black Lives Matter" has become a mantra for people protesting police violence against African Americans.

It's a hash tag, a popular t-shirt slogan and a movement that is loosely organised – by design.
Black Lives Matter was founded by three women who popularised the slogan during protests over the 2012 killing of Trayvon Martin, an African-American teen who was shot by George Zimmerman, a neighbourhood watch volunteer in Sanford, Florida.

It has a website (BlackLivesMatter.com) and a network of chapters. But the idea is bigger than the organisation.

Although the march where five Dallas police officers were fatally shot Thursday was organised by another group, news reports described it as a Black Lives Matters event.

"The convenient narrative has been for people, for the media to say, 'Well, this was organised by Black Lives Matter'," said Tezlyn Figaro, a publicist for Next Generation Action Network, the group that organised the event. The rally "had no affiliation with Black Lives Matter."

The confusion flows in part from the decentralised structure of the Black Lives Matter organisation and its founders' desire that it remain open and inclusive.

"Not everyone who shows up at a demonstration is a full-fledged member of BLM, (but) they are welcomed and encouraged to participate," Melina Abdullah, a representative of the group's Los Angeles chapter, said in a conversation with Reuters in June.

During the standoff with police negotiators Thursday, the shooter invoked the slogan, saying he was "upset about black lives matter," according to Dallas Police Chief David Brown.
The organisation disavowed the violence in a post on its web page.

"This is a tragedy - both for those who have been impacted by yesterday's attack and for our democracy," it said.

"There are some who would use these events to stifle a movement for change and quicken the demise of a vibrant discourse on the human rights of Black Americans. We should reject all of this. Black activists have raised the call for an end to violence, not an escalation of it."

That did not stop a wave of social media criticism attempting to tie the violence to the movement. But US Attorney General Loretta Lynch, speaking about the demonstrations inspired by Black Lives and other groups, drew a bright line between the gunman's actions and "lawful protest and protected speech."

"Do not be discouraged by those who use your lawful actions as cover for their heinous violence," Lynch said Friday. "We will continue to safeguard your constitutional rights and to work with you in the difficult mission of building a better nation and a brighter future."

Some said the best way to define the movement is by continuing to push a positive message. After a vigil Friday in Dallas for the slain officers, Richmond Bunch played "Amazing Grace" on his violin.

"We need to frame out a way to come back to peace," said Bunch, 35, an African-American Dallas resident and Black Lives Matter contributor. "The guy who committed this act, he does not stand for what America is."