Azealia Banks has launched a foul-mouthed Twitter tirade against Zayn Malik after accusing him of copying some of her ideas.
The trouble started after Zayn released the visual for his new track Like I Would, which Azealia felt was similar to her own work.
The American rapper posted a picture on Instagram, pointing to similarities and captioned it: "Damn, Zayn be mood boarding the fuck out of me... I'm not mad about this though. Zayn is a cutie pie."
Zayn, 23, later tweeted: "No lies ... I see you reaching but I don't care" and followed it up with a message reading: "My @'s too good for you."
It seems Azealia wasn't best pleased, and she unleashed a string of offensive tweets.
The controversial star also had a pop at UK rap in general.
Zayn later responded to the messages, saying: "@AZEALIABANKS why you been saying nasty things about me ? I wasn't talking about you lol ?"
But his question triggered another barrage of abusive tweets.
Teen Disney actress Skai Jackson also found herself embroiled in the social media war after she came to Zayn's defence.
The 14-year-old tweeted that Azealia needed to "simmer down" and labelled her "Azealia Stanks".
Azealia, 24, also had a pop at other stars during her online attack, with Rihanna and Lady Gaga among those the subject of her barbs.
The rapper's vitriolic tirade has sparked calls for her Twitter account to be suspended.