The U.S. Justice Department will hold a news conference at 2:30 p.m. EDT. (1830 GMT), a department spokeswoman said.
Citing an unnamed source, cable network MSNBC said the suspect was a man in his 50s. CNN said the arrest was made in Plantation, a city near Ft. Lauderdale, Florida. Reuters could not immediately confirm those reports.
Suspect in custody in Florida in wave of parcel bombs