The White House is currently under lockdown due to a bomb threat

.@SecretService investigating suspicious package near @WhiteHouse grounds. Road closures in effect.

— U.S. Secret Service (@SecretService) March 28, 2017

USSS is investigating suspicious package; security perimeter established & members of the public & media are being moved to safe a distance

— U.S. Secret Service (@SecretService) March 28, 2017

Other sources say it is a bit more complicated than that

BREAKING: Secret Service tells me a man approached the White House and claimed to have a bomb

— Trey Yingst (@TreyYingst) March 28, 2017

And Fox reports

The source said the man was outside the fence by the White House when he told officers he had a bomb in the bag. Officers apprehended the man, and are now inspecting the bag.

The agency said on Twitter that road closures are in effect and a security perimeter has been established.

The Secret Service said “members of the public & media are being moved to safe a distance.”

Reporters and visitors have been cleared off the North Lawn.

The incident is the latest security episode, including a string of fence-jumpers, in recent weeks.