VALPARAISO, Ind.  — A SWAT team has charged into the Indiana real estate office where a gunman has holed up after releasing several hostages.

Two loud bangs were heard Friday afternoon before officers broke window glass and rushed into the Prudential Executive Group Real Estate office in Valparaiso.

Police say a gunman who was looking for someone who he thought owed him money is inside the building. They say he held hostages for several hours before releasing the last two unharmed in recent hours.

Valparaiso Police Sgt. Michael Grennes said police received a 911 call about 10 a.m. reporting that a man with a gun had entered ther real estate office. Grennes said there were fewer than 10 people in the building when the incident began and that the last of the two hostages were released unharmed after 3 p.m.

The gunman remained inside the building, where negotiators continued to communicate with him. Asked if he still was a threat now that he was in the building alone, Grennes said, “He’s a risk to everyone right now. He’s in the building armed.”

No hostages reported being shot. Grennes said one person who was struck in the head during the incident was treated and released at a hospital.

Grennes said he did not believe the gunman was an employee of the brokerage.

“I just know the reason for him being there was a dispute over … somebody in the building, an employee in the building, owed him money. He believed that,” Grennes said.

Mack Elliott, an agent at the brokerage, told The Associated Press he was not in the office when the gunman entered, but had spoken to a couple of agents who were working at the time. He believed the incident stemmed from a dispute over a real estate transaction.