CARACAS, VENEZUELA (REUTERS) - Malien Gonzalez and Lumidia Boy, both of whom are residents of Caracas, Venezuela, are furious as the city remains without power for a fifth day on Monday (March 11), leaving them struggling to obtain water and food.

"I was going crazy with no water, electricity," Gonzalez said. "For God's sake, how long are we going to continue like this?"

Boy, who is a single mother with two children, said "everything is chaotic".

Much of Venezuela, including parts of the capital Caracas, remained without power, 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.

The opposition-controlled congress called an emergency session to discuss the power cuts, blaming negligence by Maduro's socialist government.

Maduro's rule is being challenged by congress leader Juan Guaido, who in January invoked the constitution to assume the presidency after declaring Maduro's 2018 re-election a fraud. Guaido has been recognized as Venezuela's legitimate leader by the United States and most Western countries, but Maduro retains control of the armed forces and state institutions.

The blackout, which began Thursday afternoon, has heightened frustration among Venezuelans already suffering widespread food and medicine shortages, as the once-prosperous nation's economy suffers a hyperinflationary collapse.

Food has rotted in refrigerators, hospitals have struggled to keep equipment operating, and people have clustered on the streets of Caracas to pick up patchy telephone signals to reach relatives abroad. On Monday, people formed lines to fill containers with water from the streams cascading down the mountain overlooking Caracas.