A gunman burst into a day spa where his estranged wife worked in the midwestern US state of Wisconsin and opened fire Sunday, killing three people and injuring four others, police said.
The suspect -- identified as 45-year-old Radcliffe Haughton -- was later found dead at the scene in Brookfield, a suburb of the city of Milwaukee, police told AFP.
Haughton died from a self-inflicted gunshot wound, said Brookfield police chief Dan Tushaus.
"We believe this incident is domestic violence-related," he told reporters, noting that officers discovered a small fire inside the building when they went in for the suspect and found him dead.
Women who were trying to relax by getting massages and nail treatments instead ran for their lives when the gunman entered the Azana spa, police said.
Clients stood dumbfounded in the parking lot in their white spa robes outside the locked-down crime scene, as police spent hours combing the large building, which had many small treatment rooms.
Police said Haughton's wife apparently wanted a divorce and he had slashed her car tires earlier this month, prompting her to take out a restraining order against him, Tushaus said.
But it did not stop Haughton from targeting her workplace, police admitted. They said they could not immediately say if his wife was among the dead.
The suspect's father, Radcliffe Haughton Sr, told TMJ4 News: "This is not the way I raised my son... My son is facing a domestic problem. Things happen, and some people cannot take it."
Sunday's mass shooting was the second in the US state this year. In August, six people were killed in a rampage at a Sikh temple in another suburb of Milwaukee, Oak Creek. The gunman in that incident killed himself.
Tushaus said earlier that Haughton had left behind what appeared to be an improvised explosive device, which prevented police from searching the entire two-story building.
But the police chief later said it was unclear if the propane tank was an IED or something left behind by maintenance or construction workers.
The four people injured in Sunday's shooting were not believed to be critically hurt. However, one woman who was shot in the neck may be around six months pregnant, TMJ4 reported.
Police would not immediately identify the dead, other than the shooter himself. They were not looking for any other gunmen, Tushaus said.
Television footage showed more than a dozen emergency vehicles in the parking lot of a shopping mall across the street from the spa, at least part of which has been evacuated. Tactical police teams were also on the scene.
The White House said President Barack Obama had been briefed about the incident, adding: "The president and first lady's thoughts and prayers are with the victims of this horrible shooting and their families."
Obama later called Wisconsin Governor Scott Walker and Brookfield Mayor Steven Ponto to offer his support and express his condolences, the White House said.
"Senseless acts of violence leave us with heavy hearts and many questions," Walker said in a statement.
"In the coming days, we will band together as a state and a community to seek justice for the victims and comfort those left behind."
Republican vice presidential candidate Paul Ryan, a congressman from Wisconsin, also issued a statement of support from the campaign trail in Boston.
Witness Christopher Pfeiffer said he was on his way to a bookstore in the mall when he saw a young, barefoot woman running in the parking lot.
"She was screaming, yelling, crying hysterical. She was pleading for help," Pfeiffer, 47, told the Milwaukee Journal Sentinel.
"She kept saying, 'My mother was shot.' And she mentioned that there was a gunman."
David Gosh said he was on his way home from duck hunting when he saw a woman run out into the road screaming and pounding on cars for help.
Then he saw a large man with a handgun chase after her, but luckily the police arrived with sirens blaring. Gosh said he saw the man run back into the building or possibly into the woods nearby.
"He was looking for an escape route," Gosh told the paper.
Gosh's father John said he saw two wounded women taken out of the spa -- one with a leg wound and another who appeared to have been shot in the back.
Less than a mile away is the Sheraton Hotel, where seven people were killed and four more wounded at a shooting in 2005. The shooter, who opened fire on a Living Church of God service held at the hotel, then committed suicide.