Two more staffers at Department of Energy headquarters buildings in and near Washington, D.C., have tested positive for COVID-19, Secretary of Energy Dan Brouillette said Friday.

One of these people works at the Forrestal Building in downtown Washington, another in the DoE’s Germantown building in suburban Maryland, according to the statement from Brouillette

. The Forrestal employee had not been to the building since April 5, while the Germantown employee had not been to that building since March 20, according to the statement.

DoE’s National Nuclear Security Administration manages the modernization of U.S. nuclear weapons, and owns the facilities that produce nuclear weapon components and materials.

“Because the employees were out of the building for many days prior to onset of symptoms or testing positive, no cleanings are necessary and there were no work-related close contacts,” Brouillette said.

The latest two instances of infection by novel coronavirus 2019 brings the total number of confirmed positive cases at agency headquarters to at least 12, according to statements DoE has posted online since March 18.

Some high-ranking agency officials have continued to report to Forrestal periodically since COVID-19 hit U.S. shores in January. The agency last week announced it was beginning to plan for a return of all federal employees to headquarters-region buildings. In the latest statement, Brouillette said that plan “will be initiated when the time is right.”