An exploding package sent one person to the hospital in Philadelphia early Tuesday morning.
The incident took place inside a residence around 4 a.m. in the Center City area of the city, when a package containing some kind of medication exploded, injuring a 62-year-old man.
Investigators say the victim received a Manila envelope with an "actual device."
It is not clear whether the device was placed inside at the residence or delivered by mail.
Police say the victim suffered injuries to both hands and his chest and was in stable condition at Jefferson Hospital.
Investigators believe the attack was "target specific and not terrorism."
The man's roommate told police the package exploded after it was opened, and noted that the injured man often received packages of inhalers delivered by mail.
Police said there was not significant structural damage inside the man's residence.
Bomb squad units, as well as the Bureau of Alcohol, Tobacco and Firearms and U.S. postal inspectors arrived on the scene to investigate.
This is a breaking news story. Check back for updates.