Chicago-based rapper Mello Buckzz is mourning the loss of her boyfriend and 3 closest friends after they were senselessly killed during a drive-by shooting at her album release party Wednesday evening.

Police say the deadly assault occurred just after 11 PM at the 300 block of West Chicago Avenue as a crowd stood outside what’s reported to be Artis Lounge nightclub, where the party took place.

Law enforcement says someone opened fire on the unsuspecting crowd — killing 4 and injuring 14 — before fleeing the scene.

Of the injured, 3 remain in critical condition, including a 24-year-old female who was shot in the back, a 25-year-old female who sustained a gunshot wound to the left leg and a 21-year-old female who took a bullet to the mouth.

A suspect has not yet been identified and the investigation is ongoing, police confirm.

Mello took to her Instagram to express her absolute disbelief in the hours following the shooting and to mourn the loss of her boyfriend and close ones.

She raved about the “private life” she and her better half were living together … and recounted holding his hand until she no longer could.

The “Move” hitmaker mourned the loss of her “brother” and two female companions who went by “TayyTayy” and @avi_gorgeous on Instagram as well.

Mello has not responded to TMZ’s request for comment … but she said her heart “broke into so many pieces” following the attack.