Rapper Tory Lanez is in hospital after being stabbed 14 times by a fellow prison inmate.
The 32-year-old rapper sustained wounds to his back, torso, head and face and suffered two collapsed lungs in the attack, according to a post on his Instagram account.
The Canadian hip-hop star, real name Daystar Peterson, is serving a 10-year prison sentence for shooting his ex, rap superstar Megan Thee Stallion, in 2020.
Despite his injuries, he has been able to breathe unassisted and is in "good spirits", the social media update added.
Prison officials said they were investigating the attack, which happened at the California Correctional Institution, about 75 miles (120km) north of Los Angeles, on Monday morning.
They did not comment on a potential motive.
It is the latest episode in a long-running saga, involving a bitter war of words, a dramatic trial and some of the biggest names in hip-hop.