Slipknot guitarist Mickeal Thomson was stabbed and severely injured in a knife fight with his brother Andrew Thompson, the Des Moines Register reports.
Both brothers were hospitalized with serious injuries. Mickeal Thomson's wounds included a stab wound in the back of his head.
The band's lead singer Corey Taylor wrote a Twitter message saying: "Mick Update: from what I've heard he's okay. We're sending him all your thoughts. Thank you for that."
Police told the Register the brothers were fighting with knives in the front yard of a home at about 4:25 a.m. The police report says the fight started inside and moved outside. It also said the brothers were apparently intoxicated.
Slipknot formed in Des Moines and has eight Grammy nominations and one Grammy win.