A Los Angeles police spokesman confirmed to AFP that one person was killed and two others were injured in a gunbattle on Sunday afternoon but did not reveal the identity of the deceased victim.
The sniper fled, the spokesman said.
"Having powerful enemies is a blessing," he tweeted a few hours before his death, the rapper, of a gang-torn Los Angeles neighborhood.
Coming from the hip hop underground scene, Nipsey Hussle, 33, started selling his own mixtapes (compilations), the most famous of which, "Crenshaw," was released in 2013.
His first studio album, "Victory Lap," earned him a Grammy Award for Best Rap Album last February. The reward was finally granted to rapper Cardi B.
With another rapper, YG, he made the noise in April 2016, releasing the song "FDT" (for "Fuck Donald Trump"), in the middle of the election campaign for the American presidential election.
"It makes no sense, my spirit is revolted, my God, let your soul rest in peace, and bring your divine comfort to all your relatives!" Rihanna said on Twitter.
"Party very early," wrote rapper Snoop Dogg on the Instagram. "I'm so sad now, I'll think about the good times we had together."