Civil rights activists embarked Saturday on a seven-day march to demand sweeping police reforms and denounce a US grand jury`s decision not to indict a white officer who shot dead an unarmed black teenager.
The National Association for the Advancement of Colored People (NAACP) is organizing the 120-mile (192-kilometer) "Journey for Justice" from the St Louis suburb of Ferguson where Michael Brown was killed to Jefferson City, the Missouri state capital.
A core group of around 100 marchers, who hope to be joined by thousands more by the end, are demanding the sacking of the Ferguson police chief, nationwide police reforms and an end to racial profiling.
"We will fight until hell freezes over and then we will fight on the ice," NAACP president Cornell William Brooks told an impassioned prayer service at Washington Metropolitan A.M.E. Zion Church in St Louis.
The group then boarded buses set to take them to the spot in Ferguson, where Brown was killed, and from there around 10 miles of the journey on Saturday.
"What we`re endeavoring to do here is seek justice for a grieving family as well as systemic, fundamental reform in terms of policing for an outraged community," Brooks told reporters.
It is the latest in a series of protests that erupted across the United States after a grand jury on Monday decided not to indict white police officer Darren Wilson for killing Brown in Ferguson on August 9.
The decision revived long-standing questions about how police, especially white officers, interact with African Americans -- questions raised again after last week`s shooting in Cleveland of 12-year-old Tamir Rice.
"When you have a 12-year-old child who is killed with a toy gun in his hand, there is something fundamentally wrong," Brooks said.
"This is not something we can simply chalk up to a tragic exception. This is really a sign of something much more systemic," he added.
The march comes after 15 protesters were arrested late Friday outside the Ferguson police department and after demonstrators shut down a shopping mall in St Louis, demanding a boycott of post-Thanksgiving shopping.
Monday`s announcement that Wilson will not face charges also saw largely peaceful demonstrations degenerate into looting, arson and gunfire in Ferguson.
Brooks said the seven-day march would be peaceful.
"We`re trying to use moral persuasion and we`re trying to model the kind of non-violence and civil disobedience that we believe is most effective."
A handful of other protests are also planned in the St Louis area on Saturday.
The NAACP plan to hold a rally near Missouri Governor Jay Nixon`s mansion and meet legislators to try to get their specific plans for police reform enacted.
Among their demands are requiring police to use body cameras, revise the equipping of police with military hardware, promoting diversity on the force and ending the use of major force in cases involving minor offenses.
Brooks said further demonstrations would follow to show the United States and the world that they will continue to campaign for change, accountability and justice in cases of police misconduct.
Activists say they have been encouraged by the public outrage over Brown`s death, as evident in nationwide protests that have eclipsed the reaction in similar previous cases.
"Those are the kind of things that we need to be doing," said Jylise Smith secretary for the NAACP branch in Houston, Texas.
"Not rioting, not breaking things and burning things, but actually peaceful protests to raise awareness and get the attention that it needs," she said.