Ft. Hood shooter was to be deployed to Afghanistan.

More on the Ft. Hood shootings

A US major believed to have killed 13 people in a gun attack at a Texas army base was due to be deployed soon to Afghanistan, a military official said.

Major Nidal Malik Hasan, 39, a US-born Muslim, opened fire on soldiers at Fort Hood on Thursday.

Relatives of the army psychiatrist said he had strongly opposed his deployment and had wanted to leave the army.

US officials said investigations into what prompted the attack had continued through the night.

At an early morning news conference at Fort Hood, military officials said 12 soldiers and one civilian had been killed

About US Army Major Nidal Malik Hasan, he is US-born Muslim raised in Virginia.
Joined the army and trained to be a psychiatrist. Treated soldiers returning from combat zones. Described as a devout Muslim who attended prayers regularly
It's said to have been unhappy about imminent overseas deployment

Of the 28 people who remained in hospital, 14 had required surgery but all were in a stable condition, Col Dr Steven Braverman said.

There was no comment on what might have triggered the attack.

"We're not going to speculate about motives. We'll let investigators find that out," deputy base commander Col John Rossi said.

Maj Hasan was shot four times during the attack and is currently on a ventilator in hospital, under armed guard.

The policewoman who shot him first is in a stable condition in hospital, officials said.

President Barack Obama described it as "a horrific outburst of violence".

He said: "It is difficult enough when we lose these brave men and women abroad, but it is horrifying that they should come under fire at an army base on US soil."

Images AFP, Microsoft