Rasa - Local television network WPIX reported the block of the street would be closed to cars until Sunday.
Mayor Bill De Blasio took part in the painting, posting a photo on Twitter of himself surrounded by people painting the yellow letters on the street.
"Our city isn’t just painting the words on Fifth Avenue. We’re committed to the meaning of the message," he wrote on Twitter, referencing criticism from activists who have called the creation of similar murals a "performative" distraction from substantive policy changes like cuts to police budgets or reforms to use-of-force policies.
The planned mural had provoked the ire of President Donald Trump, who slammed the mural on Twitter earlier this month as "denigrating" the street, antagonizing the city's police, and creating a "symbol of hate" on "New York's finest street".
De Blasio responded to Trump's posts, saying "Black people BUILT 5th Ave and so much of this nation. ... We are honoring them".
Several cities across the country have painted murals in support of the Black Lives Matter movement, including Washington, D.C. which painted "Black Lives Matter" in 50-foot yellow letters near the White House to honor the protesters. D.C. Mayor Muriel Bowser also renamed the location of the mural as "Black Lives Matter Plaza".