A soldier opened fire in the US army base Ft. Hood, wounding 16, killing three soldiers and himself. 

Federal officials said the shooter - Army serviceman Ivan Lopez, 34 - was being treated for anxiety, depression and was under evaluation for post-traumatic stress disorder at the time of the shooting on the base. 

He was armed with a .45-caliber Smith and Wesson semiautomatic pistol that he had purchased recently.

“We do not know a motive," Lt. Gen. Mark A. Milley, commander of the base, told reporters at a press conference Wednesday night. "But we know this soldier to have behavioral health and mental health issues.”

"In regards to the investigation, there is no indication this incident is related to terrorism, though we are not ruling anything out,” Milley added.

The shooter served four months in Iraq in 2011, Milley said, and "was undergoing treatment for depression, anxiety and a variety of other psychological and psychiatric issues.” The suspect had not been diagnosed with post-traumatic stress disorder, Milley stressed, but was being evaluated for PTSD.

In 2009, 13 people were killed and more than 30 wounded in a mass shooting at the base carried out by then-Maj. Nidal Hasan, an army psychiatrist. A U.S. Senate report following the incident described it as the worst attack on American soil since the terrorist attacks of Sept. 11, 2001, although the FBI said Hasan had no formal ties to terrorist groups despite having expressed anti-American viewpoints prior to the shooting.

Hassan was sentenced to death after admitting during his August 2013 court martial hearing to the mass shooting. He is now on death row.

We need your support so Novinite.com can keep delivering news and information about Bulgaria! Thank you!