CARACAS, VENEZUELA — Two U.S. citizens have been arrested in Venezuela, part of a group of seven whom 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. Maduro said the detained U.S. citizens were “very high level” but did not provide further details or evidence of the arrests. “Just today we’ve captured seven foreign mercenaries, including two important mercenaries from the United States,” said Maduro, who is set to take office for a third term on Friday following last July’s contested election that