Barack Obama cautioned a stunned public on Friday against drawing quick conclusions on a shooting rampage by an officer at a Texas military base that killed 13 people.

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.”