Activists raise their hands as they demand justice for the killing of Michael Brown while marching to the Thomas F. Eagleton United States Courthouse from City Hall in downtown St. Louis, Missouri, August 26, 2014. [Photo/Agencies]

ST. LOUIS - More than 100 demonstrators marched peacefully in St. Louis on Tuesday demanding the arrest of a white police officer who shot and killed an unarmed black teenager in Ferguson, Missouri.

The death of Michael Brown, 18, focused global attention on the state of race relations in the United States and evoked memories of other racially charged cases, including the fatal shooting of Trayvon Martin, a 17-year-old African-American, in Florida in 2012.

Family and supporters of Brown celebrated his life on Monday at a music-filled funeral service at a St. Louis church that rang with calls for peace and police reforms.

The Aug. 9 shooting sparked two weeks of demonstrations, some with violent clashes and scores of arrests, in which protesters demanded Ferguson Police Officer Darren Wilson be charged in Brown's death. Demonstrations have been more subdued for days.

On Tuesday, demonstrators marched a few blocks from St. Louis City Hall to the federal court building, chanting: "Fired up, fed up, time that we stand up."

The protesters, who called for Wilson's arrest and the removal of Ferguson police leaders, were blocked from walking up the courthouse steps by a group of officers, most on bicycles.

US Attorney Richard Callahan from the Eastern District of Missouri met with five of the protesters, who were allowed to enter the courthouse, and heard their demands for policing reforms and justice for Brown.

"Just the fact that he agreed to meet with us means he is taking this seriously," said Montague Simmons, a member of the Organization for Black Struggle, who attended the meeting.

Simmons said Callahan told the protesters he would raise their demands with US Attorney General Eric Holder.

Another march was expected later on Tuesday in Ferguson.

There have been differing accounts of the shooting. Police have said Brown struggled with Wilson, who shot and killed him. But some witnesses say Brown held up his hands and was surrendering when he was shot multiple times in the head and chest.

A St. Louis County grand jury has begun hearing evidence and the US Justice Department has opened its own investigation.

'CATALYST'

On Tuesday, few signs were visible at what has been the center of the protests along West Florissant Avenue in Ferguson, a St. Louis suburb.

The Missouri National Guard, which began a gradual pullout from Ferguson on Friday, was absent from a spot on the avenue it had occupied late on Monday.

A man under a gazebo sold T-shirts that read: "Hands up, don't shoot," the chant favored by demonstrators, as the temperature reached 94 F (34 C) at midday.

People gathered in small groups at the impromptu memorial set up where Brown died, and two women handed out food from a folding table.

"This community has had a story to tell for a long time and this has just been the catalyst," said Chelsea Warlick, 29, a photographer from Savannah, Georgia. The majority of people in Ferguson are black, while most of its elected officials and police force are white.

Warlick, who laid white roses by the memorial, said she was about to sign a six-month lease on an apartment in the complex where Brown lived to support the community.

"The verdict is everything. If he doesn't go to jail for what he did, this place is going to burn," she said of Wilson.