The Trump administration is closely tracking reports of a death potentially related to pneumonic plague in Russia, with officials cautioning that much about the situation remains unknown.

The Centers for Disease Control and Prevention, the State Department, the Administration for Strategic Preparedness and Response, and other agencies have been working to learn more about the reported death of a laboratory worker who was employed at an institute dedicated to studying plague and quarantines imposed on several hospitals in Siberia, four officials said, speaking on the condition of anonymity to discuss internal briefings.