An investigation is under way into the circumstances surrounding the mass shooting by a United States army officer at a military base in Texas.
Twelve soldiers and one civilian were killed and 30 were wounded when army psychiatrist Major Nidal Malik Hasan opened fire on fellow soldiers at Fort Hood base before he was shot and wounded.
The incident began about 1.30pm on Thursday as Major Hasan fired on troops at a personnel and medical centre, where soldiers who are preparing to deploy to Iraq or Afghanistan go for last-minute medical check-ups.
The 39-year-old American-born Muslim was due to be sent on a mission to Afghanistan within a month and had treated soldiers wounded in foreign wars.
The BBC reports those that know Major Hasan say he is devout, but not extremist.
However, relatives say he strongly opposed his deployment and wanted to leave the army. A cousin, Nader Hasan, told reporters Major Hasan had complained of harassment by fellow soldiers.
The United States President Barack Obama has praised the heroism of soldiers and civilians in their response to the deadly attack at an army base in Texas.
In his weekly radio address, Mr Obama said that although the shootings showed the "worst of human nature" they had also brought out "the best of America".
He described the shooting as one of the most devastating ever committed on an American military base.
Of the 28 people who remained in hospital, 14 needed surgery but all were in a stable condition, Dr Steven Braverman said.
Major Hasan was shot four times during the attack and is on a ventilator at the base hospital under armed guard.
On Friday Mr Obama ordered flags to fly at half-mast, but urged Americans not to jump to conclusions about why the attack happened.
US troops in military bases around the world have held a moment's silence to remember those killed in Texas.