The Secret Service says one of its officers shot a man carrying a gun after he refused to drop his weapon, just outside the White House on Friday afternoon.

The FBI, among other law enforcement agencies who continue to investigate the incident, say there's no known connection to terrorism right now.

From the Associated Press:

The armed man approached the checkpoint on E Street shortly after 3 p.m., and ignored repeated orders from the officer to drop his gun, according to a statement from David Iacovetti, a Secret Service deputy assistant director.The officer fired one shot at the man and the gun was recovered at the scene, Iacovetti said. The man was transported in critical condition to a nearby hospital, an emergency medical services spokesman said.

"No one within or associated with the White House was injured, and everyone in the White House is safe and accounted for," an unnamed White House official said in an email, according to Reuters.

Still, the White House was placed on an hour-long lockdown, where Vice President Joe Biden was reported as secure. President Obama was away playing golf at Andrews Air Force Base, adds the AP. First Lady Michelle Obama's office would not say whether she or the Obama daughters were at the White House at the time.

The incident follows a string of lapses by the Secret Service and calls for changes within the agency to bolster security by hiring more personnel, improving training and boosting leadership, as we've reported. In September 2014, a knife-wielding man scaled the fence on the north lawn and made it past the front door of the White House before being apprehended.

This time, says the AP, "the gunman never made it inside the White House complex, and no one else was injured, the Secret Service said."

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