Authorities ordered the U.S. Capitol Building and Visitor Center into lockdown Friday morning after police spotted what they thought was a weapon inside an employee’s backpack, according to the U.S. Capitol Police.

The lockdown was lifted after about one hour when police “determined that the item was not a threat to the Congressional community,” according to a statement from the police force. Officials declined to describe the item.

The employee had been spotted passing through the tunnel from the Rayburn House Office Building to the Capitol. Police said the lockdown was ordered “out of an abundance of caution.” Officials did not describe the job of the employee.

The lockdown, ordered at 8:42 a.m., required visitors and staff members to shelter in place, lock doors and stay away from windows. A police alert read: “If you are outside of an office building, seek cover away from the area.”

Police lifted the lockdown about 9:45 a.m.

There have been other recent security concerns involving lockdowns at the Capitol grounds. In March, a man took out a weapon, later identified as a BB gun, and pointed it at officers as he tried to get into the Capitol Visitor Center.

[Alleged Capitol gunman charged in shooting incident]

The man — Larry Russell Dawson, a 66-year-old minister from Tennessee — was shot by police. He survived. That incident happened as crowds of tourists were headed to the area’s cherry blossoms and the White House Easter Egg Roll.