A former U.S. Marine and a Florida man who were imprisoned in Venezuela have sued President Nicolás Maduro for allegedly heading a vast “criminal enterprise” that uses American citizens as bargaining chips in negotiations with the U.

Two U.S. citizens have been arrested in Venezuela, part of a group of seven who President Nicolas Maduro on Tuesday branded as "mercenaries," in the latest roundup ahead of the embattled leader's expected inauguration to a new term later this week.