U.S. Capitol on lockdown briefly

The U.S. Capitol was on lockdown and employees were instructed to shelter in place following reports of a person with a gun.

"The Senate sergeant at arms ... had earlier issued a lockdown alert for the building and visitor center, saying police activity has been reported," the Associated Press reported. " Capitol police had said they were searching for an individual but offered no details. One officer outside the Capitol said police are responding to sketchy reports of woman who may have a gun; a House Democratic leadership staffer had said the sergeant at arms office had said there had been a woman with a gun in a tunnel leading to the Rayburn House Office Building."

Photo: Monica Gonzales

The action came a day after nationwide protests over two police shootings. Five police officers were fatally shot during protests in Dallas and protesters shut down city streets and, briefly, the Connector in Atlanta.

President Barack Obama called the deaths of the police officers, felled by sniper fire, a "vicious, calculated, despicable attack on law enforcement."

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