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

He 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.