Top lawmaker declares himself Venezuela's 'acting president'

Venezuela's National Assembly head Juan Guaido declared himself the country's "acting president" on Wednesday during a mass opposition rally against leader Nicolas Maduro.

Moments earlier, the loyalist-dominated Supreme Court ordered a criminal investigation of the opposition-controlled legislature.

"I swear to formally assume the national executive powers as acting president of Venezuela to end the usurpation, (install) a transitional government and hold free elections," said Guaido as thousands of supporters cheered.