President Hugo Chavez announced Thursday that security forces arrested a U.S. citizen and suspect he is a mercenary who could be involved in an alleged plot to destabilize Venezuela if the opposition’s candidate loses the upcoming presidential election.

Chavez said the Hispanic man was detained Aug. 4 while crossing into Venezuela from Colombia. The president said the man was carrying a U.S. passport with entrance and exit stamps from countries including Iraq, Afghanistan and Libya as well as a notebook containing geographical coordinates.

The man’s identity was not released. Chavez did not say where he was being interrogated.

An official from the U.S. Embassy in Caracas did not answer repeated telephone calls seeking comment on Chavez’s announcement.