In New York, several dozens of people gathered in Manhattan's Union Square to protest against police brutality and call for meaningful change in the U.S. justice system.
Protest organizer Travis Morales of the Stop Mass Incarceration Network said the killing of Michael Brown and the heavy-handed police crackdown on protesters "opened the eyes of millions of people here and around the world."
"We need to go forward and build on this. We aim to change the thinking of millions of people and bring forth a movement of millions that will not stop until the police murder of blacks and Latino people stops," he told Anadolu Agency.
The 18-year-old's death in Ferguson ignited fierce street protests for months and saw fighting between police and protestors, making the small Missouri city a focal point of a national debate on race relations and allegations of police brutality.
In the New York protest, some were carrying signs reading "Black lives matter" -- the slogan that became a rallying cry for protesters following a series of high-profile police-involved killings of unarmed black men across the country.
"Police throughout the country continue to be militarized," said Gloria Mattera, co-chair of the Green Party of New York.
She said social problems surrounding institutional racism, housing, education and unemployment had been compounded on top of police brutality against young black people.
In Ferguson, several hundreds of people reportedly gathered in remembrance of Brown.
They observed a four-and-a-half-minute silence around noon before releasing several white doves, St. Louis Post-Dispatch newspaper said.
The duration of the tribute was meant to reflect the number of hours Brown's body remained in the street.
The crowd then held a silent march led by the slain teenager's father, Michael Brown Sr.
According to British daily The Guardian, St. Louis County Police said a person had been shot after police came under heavy gunfire in Ferguson late Sunday night. There were no details given on the condition of the person shot.
