At least one US soldier went on a shooting rampage in a Texas military base killing 11 people and wounding 31 others before being shot dead.
Two other soldiers were arrested after the shooting spree and were being held as suspects, said Lieutenant General Bob Cone, commander at Fort Hood, the largest US military base in the world.
The soldier, identified as Major Hassan Malik, opened fire with two handguns in a busy processing centre where troops go before being deployed on overseas missions in Iraq and Afghanistan.
A Fox news affiliate said the shooting happened at a training center on the base.
Army personnel told Fox news they were not sure if the victims were civilians or military personnel.
US President Barack Obama said the shootings were a 'horrific outburst of violence'.
Fort Hood is the largest US military base in the world , it is located about 96km from Austin.
