Cardi B performs during the 2018 iHeartRadio Music Awards. Picture: Chris Pizzello/Invision/AP

Cardi B has donated $8,000 (about R107 834) to the family of a 15-year-old boy, Lesandro 'Junior' Guzman-Feliz, who was stabbed to death in a brutal attack.

The 25-year-old rapper has pledged the sum to a GoFundMe account set up in memory of Lesandro 'Junior' Guzman-Feliz after the teenager was dragged out of a shop and stabbed to death in The Bronx, New York, where Cardi was born and raised. 

She wrote on Instagram: "#justiceforjunior 🇩🇴R.I.P. .These Bronx streets are ruthless (sic)"

Cardi - who made the donation under her real name Belcalis Almanzar - also called for the police to do more in such situations. 

She added: "What p**s me off the most is that these BX cops be harassing the s**t outta people then they see a boy bleeding to death and ask what happen ?"uuuummmmmmmm How bout you call the ambulance like ya be calling for back up when ya see n***as smoking in front of a building !!!!! People be like"call the police!" Call the police!!" But for what the operators be asking you questions for like 4 minutes on the phone with an attitude and the cops come maaa lateeee. (sic)"

Cardi posted a picture of Junior lying in a hospital bed, and later shared a clip of his 48-year-old mother Leandra Feliz thanking the rapper and others for their heartfelt donations. 

In response, the 'Be Careful' hitmaker encouraged her Instagram followers to "check out" the GoFundMe account, which has raised more than $147,000 for Junior's family so far. 

She wrote on Instagram: "Shheeeshhh this made me teared and made me feel soooo special like i feel maa special

"There's a gofundme account for Junior make sure ya check it out ! (sic)"

Dermot F. Shea, chief of detectives at the New York Police Department, took to Twitter to appeal for the public to help out with their enquiries. 

He wrote: "In the Bronx on 6/20, 15-yr-old Junior Guzman-Feliz was fatally stabbed by the men in the photo (on right). He was never going to give up on his dream of being an NYPD detective & WE'LL NEVER GIVE UP ON HIM.

"Someone out there knows these men, all wanted for the brutal murder of 15-yr-old Lesandro "Junior" Guzman-Ortiz in #thebronx. Take a good look at each. It's up to you to help us get #JUSTICEFORJUNIOR. (sic)"

On Sunday night he wrote: "INTERIM UPDATE: We have made arrests regarding the murder of 15-yr-old Lesandro "Junior" Guzman-Feliz. Confirmed details to follow. This is still an active investigation. Your tips have been invaluable! Please keep them coming. 800-577-TIPS. #justiceforjunior #GangFreeBronx (sic)"

Derek Grullon, Junior's brother-in-law, has claimed members of a gang have reached out to him on Facebook claiming they killed his relative in a case of mistaken identity. 

He told the New York Daily News: "They said, 'We had the wrong person.' "

Junior's brother-in-law Ione Gutierrez set up the GoFundMe account in memory of Junior following his "sudden and tragic" death. 

He wrote on the page: "Hey everyone I opened up a gofundme account for my brother in law and he's family due to financial difficulties at this moment since he's death was so sudden and tragic. He was 15 yrs old and was stabbed to death by a group of multiple men Anything donated will be greatly appreciated. We appreciate your help and your prayers thank you very much. (sic)"