The White House is on lockdown after a passenger vehicle struck a security barrier.
The U.S. Secret Service tweets that the vehicle ``did not breach the security barrier of the White House complex.''
The agency adds that the female driver of the vehicle was ``immediately apprehended.''
Witnesses saw a commotion on the White House grounds as security officers responded.
President Donald Trump is hosting Australian Prime Minister Malcolm Turnbull at the White House. Turnbull is remaining at the White House as the incident is being investigated.