Two people wait to leave the University of Pittsburgh School of Medicine after the area was locked down by police due to a shooting at the Western Psychiatric Institute and Clinic of University of Pittsburgh Medical Center in Pittsburgh, Pennsylvania March 8, 2012. [Photo/Agencies]

WASHINGTON - A mass shooting incident occurred on Thursday at Western Psychiatric Institute and Clinic in Pittsburgh, the US state of Pennsylvania, according to a report by local TV station WPXI-TV.

The shooting happened in the afternoon in the hospital lobby. According to initial reports, as many as five to seven people have been wounded. A police officer was shot in the leg.

It was unclear what agency the officer is with, and authorities had no information on other victims' conditions.

WPXI said one shooter was found dead in a hospital hallway, and a possible second shooter may be loose somewhere inside of the facility. The SWAT team was responding to the scene.

Police say the nearby Carlow University and the University of Pittsburgh are on lockdown.