Rapper Nas and hip-hop moguls Russell Simmons and Kevin Liles joined forces on Saturday (13Dec14) to hit the streets of New York as part of a demonstration against a spate of recent police killings of unarmed black citizens.

An estimated 27,000 people took part in the Millions March NYC protest to demand justice over the controversial grand jury decisions not to indict the officers responsible for the shooting death of Michael Brown in Ferguson, Missouri and the killing of Eric Garner, who died in Staten Island, New York after he was placed in a chokehold.

The march also raised awareness about other victims Akair Gurley and Tamir Rice, who were also killed in police encounters in recent months.

Nas and Simmons shared photos from the protest on their Instagram and Twitter pages, while stars including singer Alicia Keys, rapper Nicki Minaj and Sean 'Diddy' Combs shared information about the march on social networking blogs to encourage others to join in.

Similar protests took place in cities such as Washington, D.C., San Francisco, California, and Boston, Massachusetts on Saturday.

The Millions March event took place three days after Simmons teamed up with Jay Z to meet with New York Governor Andrew Cuomo to discuss a potential review of the judicial system in the wake of the police killings and controversial grand jury decisions, which have sparked demonstrations across the U.S.