A soldier opened fire at the U.S. Army post of Fort Hood in Texas on Wednesday, killing three people and wounding 16 others before killing himself, the commanding general of the post said.

U.S. President Barack Obama said he was "heartbroken" that another shooting had occurred at the Fort Hood Army post. (Photo source: chinanews.com)

Several hours after the shooting, commander Lt. Gen. Mark A. Milley confirmed to the media that the shooter, an Army specialist who had served inIraqand was being treated for mental health issues, had died of a self-inflicted gunshot wound.

Milley said the soldier first walked into a medical support building on Wednesday afternoon and opened fire. He then went out, got into a car and drove to a second building. He fired several shots while driving.

After he went inside the second building, he resumed shooting before confronted with a military officer. The gunman then turned the handgun to his head and fired, Milley said.

Milley declined to identify the shooter. But U.S. media, quoting different sources, identified him as 34-year-old Ivan Lopez. Lopez reportedly worked as a truck driver on the post and had arrived at Fort Hood in February from another installation.

Milley said the shooter's motive remained unclear, but the shooting did not appear to be related to terrorism. Some reports said the shooting seemed to have resulted from disputes between soldiers, but there is no immediate confirmation.

Milley said the gunman used a .45-caliber Smith and Wesson automatic pistol that he recently purchased locally. The weapon was not registered on base as required, he said.

Three people were shot dead and 16 more wounded in the shooting. All of the victims are military members. Several among the wounded are in critical condition, according to media reports.

Previously the military base was put on lockdown as authorities investigate. The lockdown was lifted on Wednesday night and all traffic resumed. A college campus and a hospital near Fort Hood were also evacuated as a precaution.

U.S. President Barack Obama said he was "heartbroken" that another shooting had occurred at the Fort Hood Army post.

"We are going to get to the bottom of exactly what happened," Obama told reporters in Chicago, where he is traveling for Democratic fundraisers. "We're heartbroken that something like this might have happened again."

Fort Hood was the scene of a shooting rampage on Nov. 5, 2009, when Nidal Malik Hasan, an Army psychiatrist, opened fire at a soldier readiness center on the base. The shooting left 13 people dead and more than 30 others wounded. It was the worst shooting ever to have taken place on an American military base.

Source: Xinhuanet