The commander of a US army base where a soldier shot three colleagues says an "escalating argument" was the most likely cause of the attack.

The soldier who killed three people before committing suicide in an attack on the same Texas military base where more than a dozen people were shot dead in 2009 had shown no recent risks of violence, officials say.

A soldier opened fire on fellow service members at a US military base, killing three people and wounding 16 before committing suicide.