Foreign rescue teams and aid reached the hardest-hit areas nearly two days after magnitude 7.2 and 7.5 tremors devastated parts of Caracas and surrounding areas.
The government estimated 172 remained trapped under the rubble on top of 920 confirmed fatalities and 3,360 injuries. A website taking reports of the missing listed over 50,000.
The economic toll also came into view on Friday, with a UN report estimating direct damage from the quakes at about $US6.7 billion.
Moron, near the epicentre, was still without electricity on Friday afternoon, the local fire chief told Reuters. A transmission line outage was slowing efforts to have full service restored at a key port, a refinery and a petrochemical complex, sources said.
Reuters witnesses traversed highways cracked by the quakes and passed dozens of buildings reduced to broken concrete and twisted metal. Some ruins were spray-painted with building names to help rescuers identify locations.
Traffic was heavy heading into the hardest-hit region of Venezuela's La Guaira state, both with official cars, including trucks carrying soldiers, and what looked like private vehicles.
The quakes destroyed at least 100 buildings, including high-rise apartments, in La Guaira.
Residents digging through debris with their hands and improvised tools decried a lack of heavy equipment, while volunteers brought supplies on motorcycles from Caracas and Valencia.
Jennifer Palacios, 25, said the quakes struck when she briefly left her home in the city's eight-tower Hugo Chavez housing complex, named after Venezuela's late socialist leader, burying her six-year-old son and five other relatives. Their fate remained unknown.
"It's the community that has managed to get people out alive," she said, sitting on a plastic chair in front of the rubble. "We need them to bring cranes to move the slabs. There are still people trapped."
Police, national guard and other officials did not intervene in the looting, based on what Reuters witnesses saw, but were directing traffic toward Caracas.
The government of interim President Delcy Rodriguez, who took power after the United States captured her predecessor in January, has pledged a massive deployment of assistance and was shown on state television visiting La Guaira.
Rodriguez, who said La Guaira state would be "militarised" to facilitate rescue work, thanked motorcycle caravans bringing supplies and said the government had distributed 2,600 tons of food.
A Reuters team saw police and national guard motorcycle patrols on the road to La Guaira's hard-hit Los Corales community. Yet help was patchy on Friday, with firefighters, police, civil protection and the military on the streets in some places but absent or minimally present in others.
The disaster could have political consequences for Rodriguez, who has sought to portray herself as an agent of political change even though she served as vice president to the ousted Nicolas Maduro.
Venezuela's oil production level was not affected by the quakes, with output at 1.2 million barrels a day, oil minister Paula Henao said in a radio interview.
Oil executives and workers in Venezuela's energy sector said the sector had escaped major infrastructure damage, but power outages and port delays are expected to curtail oil output.
Foreign rescue teams - including some from countries that have opposed Venezuela during decades of international isolation, political repression and economic deterioration - began arriving into Friday, with a small contingent from the Dominican Republic the first to reach La Guaira.
Mexico, Colombia, India and Spain were among countries that sent in rescue teams, supplies and equipment.
The US said it was mobilising $US150 million in aid and easing sanctions while the US military dispatched two ships and said helicopters and aircraft would support rescue efforts.
The quakes struck a nation already weakened by decades of economic and political turmoil that has impoverished residents, driven millions abroad and eroded basic infrastructure and services.
The US Geological Survey estimated more than 10,000 deaths were possible, which would place the quakes among the deadliest earthquakes in Latin America in the last century.
Nearly seven million people could be affected, said the UN's migration body, which was supplying emergency shelter and other relief supplies.
