Three people were dead and four others wounded in a mass shooting Sunday at a spa in the U.S. state of Wisconsin, police said. The gunman died of a self- inflicted gunshot wound.

The suspect, 45, was of Brown Deer, Wis., police said.

Police later found the suspect dead at the scene at a shopping mall in the suburb of Milwaukee. It is not known if the suspect is one of the three killed or if he is in addition to the three originally reported.

Authorities spent much of Sunday afternoon looking for the suspect.

They say they believe the shooting was related to a domestic dispute.

The shooting happened about 11 a.m. at the spa, about 10 miles west of Milwaukee. An improvised explosive device was found at the spa, and a bomb squad was investigating, police said.

Local court records show that a temporary restraining order was issued Thursday against the suspect. A hearing was held that day, and the suspect was ordered to deliver his firearms to the sheriff and to have no contact for four years with the complainant.

Records suggest that the suspect had endured several years of financial problems. His home has been listed as for sale by owner, police said.

It was the second mass shooting in the Milwaukee area in just two months. A gunman opened fire at a Sikh temple near Milwaukee on Aug. 5, killing six people and wounding at least three others, before being shot to death.

Three people were killed and a fourth was injured last week when a gunman stormed a hair salon in Casselberry, Fla.