Philadelphia police are investigating an alleged plot to attack the Pennsylvania Convention Center Thursday night, ABC 6 Action News reported.
The local news station reported that police received a tip about a family driving up from Virginia in a Hummer, headed to the convention center.
A weapon was recovered from the vehicle and a man taken into custody.
More than 58,000 ballots are still being counted in Philadelphia County, according to the Department of State, many at the convention center.
No injuries were reported.