Police guard the site of a mass shooting at a bar in Thousand Oaks, California, U.S. November 8, 2018. REUTERS/Ringo Chiu

WASHINGTON (Reuters) - President Donald Trump said on Thursday he had been briefed about the deadly mass shooting in southern California and that the FBI was on the scene at a bar where a gunman killed 12 people.

“I have been fully briefed on the terrible shooting in California. Law Enforcement and First Responders, together with the FBI, are on scene,” he wrote on Twitter.