Venezuela detains opposition leader Guaido's uncle

ALEX WONG / GETTY IMAGES NORTH AMERICA / AFP

Venezuela has admitted to detaining the uncle of opposition leader Juan Guaido and accused him of trying to smuggle "dangerous materials" into the country.

"He's detained, not forcibly disappeared, he's detained for bringing prohibited substances onto a flight," Vice President Diosdado Cabello said on Wednesday.

He also presented images of a bulletproof vest, alleged explosive material and an electronic file containing information about "operations against Venezuela" that allegedly belonged to Juan Jose Marquez.

Guaido, who returned from an international tour rallying support for his party, has accused President Nicolas Maduro of using his uncle as a means of threatening him to back down.

"I hold you responsible, usurper Nicolas Maduro, and each one of your minions in Maiquetia for what happens to Juan Jose Marquez," he said.