San Bernardino shootings: Obama says attackers 'may have been radicalised'

President Obama has said the couple behind Wednesday's mass shooting in in San Bernardino, California "may have been radicalised" but the US "will not be terrorised" by the attack.

The president used his weekly to address focus on the shooting, referencing the country's hotly debated gun laws in his address and calling on Congress to close a loophole that permits some people branded too dangerous to fly to buy weapons.

On Friday, the FBI confirmed it was treating the attack by Syed Rizwan Farook and his wife Tashfeen Malik as "an act of terrorism".

Laura Bicker reports from San Bernardino.