US President Barack Obama has urged people not to jump to conclusions while law enforcement officials gather facts about the mass killings at Fort Hood.
The president has ordered flags to be at half staff at the White House and other federal agencies until Veterans Day on Wednesday as a tribute to those who lost their lives.
The suspected shooter, Maj. Nidal Malik Hasan, went on a rampage that left 13 people dead and injured 30 others at the sprawling Army post in Texas.
Obama promised to update the US as his administration learns more about what happened.
Hasan was shot and remains hospitalized. The motive for the incident is unclear.
The remarks were Obama's second on the incident. He deplored it after it happened on Thursday.