(Reuters) - Two people were killed and seven people were wounded in a shooting on Thursday at a psychiatric institute at the University of Pittsburgh Medical Center, and one of the dead was the gunman who walked into the clinic's lobby armed with two semi-automatic handguns, authorities said.
The identities of the gunman and the victims were not immediately released, and authorities at a media briefing did not reveal any details of what the gunman's motive may have been.
The gunman entered the lobby of the Western Psychiatric Institute and Clinic at UPMC shortly before 1 p.m. with two semi-automatic handguns and began firing, according to police and Mayor Luke Ravenstahl.
University and Pittsburgh City police who arrived on the scene shot back, the mayor said. "Police did engage in gunfire," he said. "It is too early to say what gun killed the two deceased."
Seven people, all of them adults, were wounded. Five of them were being treated at UPMC Presbyterian, where two of them were in intensive care, said Dr. Donald Yealy, chief of emergency medicine at UPMC.
All of the wounded were expected to survive, Yealy said. Two other victims were treated at the hospital and released.
The three men and two women still treated at the hospital for gun shot wounds ranged in age from 35 to 64. Of them, two were in serious condition and three were listed as fair, the hospital said in a statement.
Authorities also said a UPMC police officer was grazed in the leg by a bullet.
Of the wounded, at least five were Western Psychiatric employees and one was believed to be a visitor, authorities said.
Western Psychiatric Institute treats more than 25,000 children, adolescents and adults a year for a range of disorders including Alzheimer's disease, depression, schizophrenia and substance abuse, according to its website.
In response to the shooting, UPMC said in a statement that it would review all security procedures in the coming days.
None of its 289 patients were evacuated following the shooting, hospital officials said.
Earlier reports of a second gunman were inaccurate, authorities said.
"It appears at this point that he acted alone," Ravenstahl said.
"This is a tragic day, a sad day, a senseless day in many ways," the mayor added.