Venezuela's opposition leader emerged from hiding on Saturday, declaring "We have never been so strong," as President Nicolas Maduro slammed what he called attempts to "usurp the presidency" following last week's disputed election.

Thousands gathered peacefully across Venezuela, including in the capital Caracas where Maria Corina Machado thrilled supporters with a surprise appearance in a truck bearing a banner reading "Venezuela has won!"

Machado, who spent much of the week in hiding after Maduro threatened her with arrest following deadly post-election protests, had backed the candidacy of Edmundo Gonzalez Urrutia after she herself was banned from running.