Much of Venezuela, including parts of the capital Caracas, remained without power on Monday for a fifth day, crimping vital oil exports and leaving people struggling to obtain water and food.

President Nicolas Maduro, who has blamed the unprecedented blackout on sabotage by the United States at Venezuela's Guri hydroelectric dam, ordered the suspension of classes and the working day, as he had on Friday.

Sources in the oil sector, OPEC member Venezuela's main source of foreign earnings and a vital generator of revenue for Maduro's government, said that exports from the primary port of Jose had been halted by the blackouts.