WASHINGTON (AP) — Thousands of protesters have marched to the Capitol, where relatives of several black men who died in incidents with white police officers are addressing the crowd.

Civil rights organizations held the Saturday march and rally to bring attention to such deaths and call for legislative action.

Among the speakers were civil rights leader The Rev. Al Sharpton; the widow of Eric Garner, killed by an officer in New York; the parents of Michael Brown, an 18-year-old killed in Ferguson, Missouri; and the mother of 12-year-old Tamir Rice, a 12-year-old killed in Ohio as he played with a pellet gun in a park.

Many asked the crowd to chant, “I can’t breathe.” Garner had gasped those words before his death while being arrested for allegedly selling loose, untaxed cigarettes.

Protestors’ signs displayed that sentence as well as “Black Lives Matter” and “Who do you protect? Who do you serve?”