The soldier suspected of opening fire at a U.S. Army base in Fort Hood, Texas is alive.

Earlier reports said authorities killed the gunman after dozens were shot.

The soldier, has been identified as Maj. Nadil Malik Hasan. Two other soldiers suspected in the attack were detained, but they've since been released.

Information is beginning to trickle out about Hasan. He was a psychiatrist at Walter Reed Army Medical Center for six years before being transferred to the Texas base in July.

Federal law enforcement officials also say Hasan had become known to them at least six months ago because of Internet postings that discussed suicide bombings and other threats. The postings appeared to have been made by him, but authorities are still trying to confirm that he was the author. They say an official investigation was not opened.

Investigators are still trying to determine if Hasan is a birth name, or if it changed in a conversion to the Islamic faith at some point in his life.

The shooting began around 1:30 p.m. at the base's Soldier Readiness Center, where those who are about to be deployed or who are returning undergo medical screening.

A graduation ceremony for soldiers who finished college courses while deployed was going on in an auditorium at the Readiness Center at the time of the shooting, said Sgt. Rebekah Lampam, a Fort Hood spokeswoman.

The base was immediately put into lock down after the shootings. The injuries of the 31 wounded are varying.

In Washington, President Barack Obama called the shooting ``a horrific outburst of violence.'' He said it's a tragedy to lose a soldier overseas and even more horrifying when they come under fire at an Army base on American soil.


``We will make sure that we get answers to every single question about this horrible incident,'' the commander in chief said. ``We are going to stay on this.''

Covering 339 square miles, Fort Hood is the largest active duty armoured post in the United States. Home to about 52,000 troops as of earlier this year, the sprawling base is located halfway between Austin and Waco. It has been continuously used for armoured training and is charged with maintaining readiness for combat missions.

The death toll still remains at 12 after one of the 31 injured died.