There are reports Cardi B and Nicki Minaj have got into a major fight in New York.
Video of what happened isn't very clear, but Cardi left a New York Fashion Week event with a bump on her head.
Posting on Instagram, accusing Minaj of attacking her skills as a mother.
The 25-year-old said she had "let a lot of s*** slide" and referred to "sneak disses", but said that she would not allow the person she was upset with to "mention my child".
The rapper, who gave birth to daughter Kulture in July, claimed the person had been liking social media comments questioning her parenting skills.
Nicki Minaj attends the Harper's BAZAAR "ICONS by Carine Roitfeld" party at The Plaza, New York | Image: Charles Sykes/AP/Press Association Images
Videos emerged on Twitter, appearing to show the altercation, but it is unclear who was involved.
TMZ claims the new mother lunged towards the 35-year-old, whose real name is Onika Maraj, but was held back by security.
Later, she reportedly threw a shoe in the direction of her rival and her entourage.
But sources close to Cardi B told the website the artist was not looking for a fight and that she only wanted to address "lies" that were allegedly being spread.