The passenger to whom the bag belonged to has been detained while four of Miami International Airport's six concourses have been evacuated.
The Transportation Security Administration (TSA) has not revealed any details on the suspicious item detected by a screener nor the identity of the passenger.
"The passenger was located and is now in law enforcement custody," the federal agency responsible for air travel security, TSA, said in a statement.
"To ensure public safety", Terminals E, F, G, and H have been evacuated along with airport roadways.
Evacuations began right after the suspicious item was detected at around 9 pm on Thursday, Sep 2 and continued early Friday, Sep 3.
Miami-Dade police, a bomb squad, fire officials and other law enforcement agents conducted over-night operations to ensure the airport was safe.