The president made the comments as the commander of Fort Hood, the US’s largest base for deployments to Iraq and Afghanistan, quoted witnesses as saying the suspected gunman, Major Nidal Malik Hasan, shouted the Muslim declaration “Allahu Akbar” – God is great – as he opened fire. Speaking at the White House, Mr Obama said: “We don’t know all the answers yet, and I would caution against jumping to conclusions until we have all the facts.”

Major Hasan, who was shot by a civilian policewoman in the incident, was on Friday unconscious and on a ventilator in custody.

Lieutenant General Robert Cone, base commander, said in television interviews that military officials would interrogate him as soon as possible. ...