Two federal Bureau of Prisons employees have tested positive for coronavirus, according to Sue Allison, an agency spokesperson.

The tests came back in the past 24 hours and represent the first known cases of the virus in the federal prison system, according to the BOP. No inmates have yet tested positive.

One staffer worked at a medium security prison in Berlin, New Hampshire. The other worked at an administrative facility in Grand Prairie, Texas, according to Allison. Their identities and positions were not provided.

The BOP has notified local health officials and is doing a risk assessment internally to determine who might have been exposed to the infected workers, Allison said.