Three people have been killed and four wounded in a shooting in the US state of Wisconsin, the BBC reported.

An unknown assailant on Sunday opened fire at the Azana spa in Brookfield, Wisconsin. Police arrived at the site after receiving reports from witnesses that they had seen a lone gunman there.

The suspect, identified as Radcliffe Haughton, 45, was later found dead at the scene with a self-inflicted gunshot wound, police said.

The incident was reportedly caused by a domestic dispute.