At least four people were killed Wednesday in a shooting on a hospital campus in Tulsa, Oklahoma, police said in a news conference Wednesday evening. The gunman is also dead, police said. Authorities believe the shooter's gunshot wound was self-inflicted, Tulsa Police Department Deputy Chief Eric Dalgleish said in the news conference.

Several people were also wounded, though no one has life-threatening injuries, police Capt. Richard Meulenberg told CNN on Wednesday night. Dispatchers received a call about an active shooter at the Natalie Medical Building, a physicians' office building on the St. Francis Hospital campus, shortly after 4:50 p.m. local time, Dalgleish said.

Officers responded to the scene within minutes and made contact with victims and the suspect roughly five minutes later, Dalgleish said. The officers who arrived could hear shots inside the building, which directed them to the second floor, according to the deputy chief.

"The scene is fairly limited to one section of that floor, on the second floor," Dalgleish said. At least part of the scene was in an orthopedic office on that floor, according to Dalgleish. 📷

No officers were injured, he added. Investigators are interviewing witnesses that were in the building, Dalgleish said. One witness was found locked in a closet, he said.

Police said they are "getting close" to identifying the suspect, who Dalgleish said had one rifle and one handgun with him. "It appears both weapons, at one point or another, were fired," the deputy chief said.

Authorities were notifying the victims' families Wednesday night, Meulenberg told CNN. "It's a horribly tragic event," Meulenberg said. "I'm very, very proud of the officers for getting there as quickly as they did, very well potentially stopping more people from losing their life today."

Tulsa Mayor G.T. Bynum expressed "profound gratitude" for the first responders who "did not hesitate today to respond to this act of violence." "The men and women of the Tulsa Police Department did not hesitate," the mayor said.