Grammy-nominated rapper Nipsey Hussle was shot dead in the US city of Los Angeles Sunday, sparking an outpouring of grief from fellow celebrities as the city's mayor blamed "senseless gun violence."

According to local media reports, Hussle was shot in front of his own clothing store Sunday afternoon at close range, by a man who fled in a getaway car.

"Our hearts are with the loved ones of Nipsey Hussle and everyone touched by this awful tragedy," LA Mayor Eric Garcetti tweeted.

A police spokesman told AFP the suspected shooter remained at large.

"LA is hurt deeply each time a young life is lost to senseless gun violence," Mr Garcetti said.

The Los Angeles Times reported the shooting was "likely planned and gang-related."