Capitol police said Thursday that shots were reported fired outside the Capitol and all staffers were warned to stay inside and away from doors, the Washington Times reports.
“If you are in an office building, shelter in place,” an audio message broadcast to Capitol offices said, also warning those on the grounds outside to seek cover.
Officers were scouring the area just outside the Senate with rifles at the ready. At one point an officer was crouched with a rifle to his shoulder as he guarded visitors who had been walking up a path around the Capitol.
A notice broadcast on the internal television system ordered employees to “close, lock and stay away from external doors and windows.”
Minutes after the alert went out, police had barricaded off Constitution Avenue and had shut down the grounds.
US Capitol Police said a police officer was injured, the Associated Press reported.