The US State Department's unclassified email systems were the victim of a cyberattack in recent weeks, around the same time as the White House systems were breached, according to media reports.
The State Department's network was infiltrated last month, but the department did not disconnect the affected systems until over the weekend, according to federal technology information website nextgov.com.
It said there was abnormal activity in the email system as recently as late October.
The State Department breach follows similar intrusions disclosed in recent months at the White House, the Office of Personnel Management and, just last week, U.S. Postal Service and National Oceanic and Atmospheric Administration.
USPS said it was the victim of an intrusion that may have compromised the personal information of more than 800,000 employees, as well as data on customers who contacted its call center during the first eight months of this year. In the NOAA case, four of the agency's websites were affected.
The State Department cyberattack was first reported Sunday by The Associated Press.
The intrusion did not affect any of the department's classified systems, the New York Times reported.