ST. LOUIS : Thousands of people took to the streets of the midwestern US city of St Louis on Saturday to protest police tactics in the wake of the racially charged shooting of an unarmed black teenager.

Demonstrators gathered downtown in the morning hours, some hoisting signs reading “Black Lives Matter!” and “Justice for All.”

The protest was part of a so-called “weekend of resistance” organized in the aftermath of the August 9 shooting death of 18-year-old Michael Brown in the nearby suburb of Ferguson, Missouri.

Police say officer Darren Wilson - who is white - shot Brown after he attacked him and tried to seize his gun, but witnesses say the unarmed teen was shot after he put his hands up in the air.

The protests began Friday and are due to last four days.

On Saturday, women held up a large white banner dotted with colorful paper cutouts of hands and hearts in solidarity with mothers who say they have lost their children to police violence.

The diverse crowd spanning several generations marched to a plaza in downtown St. Louis, where they took part in a rally.

Some protesters carried a large paper and cardboard replica of Brown with his hands up in the air. Others wore black t-shirts with the slogan, “Hands Up Don’t Shoot!”

An AFP journalist estimated the crowd at more than 5,000 people. Police and organizers did not immediately respond to requests for turnout figures.

Unlike at previous protests, there were no immediate reports of arrests, violence or property damage.

“Everyone here is peaceful, calm & respectful #AGoodDay,” St. Louis Police Chief Sam Dotson wrote on Twitter. “Organizers are trying to keep everyone on the sidewalk.”

Dotson and Missouri Highway Patrol Captain Ron Johnson, who was appointed to coordinate the official response to the uproar after Brown’s death, were on hand during the marches, and spoke with participants.

About 200 people marched separately on the police headquarters in Ferguson, where 50 officers were posted outside the building. An evening vigil was planned at the site of Brown’s death.

Outrage in the area grew this week after an off-duty white police officer shot dead a black teen in St Louis.

Police said the officer was moonlighting as a security guard when he shot and killed the 18-year-old, and said the teen opened fire first.

In Ferguson, Brown was shot at least six times by Wilson, and his body was left in the street for several hours.

The incident led to weeks of violence in the St. Louis suburb of 21,000, which has an African-American majority and an overwhelmingly white police department and town government.

Some demonstrators complained that police used undue force during peaceful protests.

Brown’s death prompted a nationwide discussion about race and led to a Department of Justice probe into the Ferguson police department.