A MASS shooting at a military base in the US has left 12 people dead and dozens more injured, an army official confirmed tonight.

Lieutenant General Bob Cone, of Fort Hood in Texas, said a gunman open fired inside a station at which soldiers are readied for deployment to Afghanistan.

The killer, believed to be a member of the US army, was shot dead at the scene. Two other suspects have been arrested in relation to the incident.

At least 30 soldiers were injured alongside the dozen killed outright.

The Fort Hood compound - the US's largest military base - was immediately placed under lock down, with all vehicles barred from entering or leaving the complex.

President Barack Obama met with aides in the White Houses Situation Room after being informed of the incident.

In brief remarks given after speaking with senior military personnel, the president said: "We do not know all the details at this moment.

"What we do know is that a number of American soldiers have been killed and even more have been injured in a horrific outburst of violence."

Fort Hood is a sprawling 340 square mile military installation situated 50 miles south of Waco.

It houses some 4,929 active duty officers and 45,414 enlisted members of the army.

Today's shootings began at 1.30pm local time (7.30pm GMT).

The assailant entered the base's readiness centre - where soldiers about to be deployed or just returning from action undergo medical checks - armed with two handguns.

After the initial attack, two other soldiers acting suspiciously were picked up at a separate location within the complex, Lt Gen Cone said.

Army officials said it was too early to speculate on any motive.

The incident comes at a time when the US army is suffering an increase in suicides and stress-related disorders.

The suspected gunman, who was among the 12 killed in the incident, was named in reports as Major Malik Nadal Hasan.