Packages found at New Haven’s federal courthouse Monday morning are being investigated for suspicious activity.

Officers from the New Haven Police Department and its Hazardous Devices Unit arrived at the courthouse — located at 141 Church St. — before 7 a.m. Monday, after federal marshals and security personnel discovered the two packages. Writing on the boxes prompted the HDU to run them through x-rays examining their contents.

The x-rays revealed that the packages did not contain anything hazardous or explosive, NHPD spokesman David Hartman said in a release Monday morning.

“The U.S. Marshal’s Service has taken over the investigation. NHPD’s involvement was limited to traffic control, evacuation directives and the HDU portion of the investigation,” Hartman said in the release, adding that he had no information on the packages’ contents or what was written on them.

Though the courthouse and surrounding area between Chapel and Elm Streets were evacuated as HDU officers responded, traffic resumed before 9:30 a.m.