In the hours after Venezuela’s devastating earthquakes, residents dug through mountains of collapsed concrete with their bare hands. Some pleaded on social media for excavators. Rescuers worked without generators or the demolition tools needed to reach survivors trapped beneath collapsed buildings.

Volunteers and experts say the country lacked the specialized equipment needed for a disaster of this magnitude, slowing rescue efforts during the critical first days after the quakes, which so far have killed more than 1,900 people.

“Desperation is reigning because everyone wants rescuers at their specific location, but the rescuers know that without tools, they can’t do anything,” said Samuel Hernández, a 34-year-old mechanical engineer volunteering in La Guaira, a northern coastal region most ravaged by the temblors. “It’s the ugliest thing I’ve seen in my life. I feel like crying every second I am down there.”

Venezuela had shortages of a wide range of specialized equipment, said Jacobo Vidarte, an emergency management specialist in the country. That included fiber-optic cameras to search under collapsed buildings, sound-detection equipment to identify survivors, high-frequency radios that work inside concrete structures, hydraulic lifting equipment, power cutters, proper flashlights and trained search dogs.

Equipment like that can make a big difference in finding people in the first days after a disaster, before the window for finding survivors starts to close, experts said.

Foreign countries are sending in hundreds of rescue workers as well as trained search dogs, but international search teams are forced to make impossible triage decisions because of the volume of building collapses.

The paucity of important equipment in Venezuela is part of what critics have portrayed as the government’s woeful disaster response and a byproduct of years of mismanagement and corruption that have hollowed out the state.

Videos posted on social media from collapsed apartment buildings across La Guaira captured residents’ growing desperation. In some cases, people had to claw at debris with their hands in the initial hours after the quakes.

About 48 hours after them, Ángel José Rodríguez Salcedo appealed by video for the authorities to send heavy machinery to his apartment building, saying volunteers had rescued six people but could not lift the concrete slabs trapping others who still showed signs of life.

“We need more support — but support with equipment,” he said. “There are still many people trapped in the building.”

In another video, a man identified as Erik Poletti said neighbors pooled their own money to rent an excavator and backhoe loader. They could no longer wait, he said, for the authorities to clear the debris at a building in La Guaira where his son and ex-wife were trapped.

Mr. Poletti said Venezuela’s Civil Protection agency, Caracas firefighters and a rescue team from the Dominican Republic had visited the site a day earlier, with search equipment, but not with machinery capable of removing rubble.

“We had to start doing this ourselves,” Mr. Poletti said.

He added that the arrival of international rescue teams had started bringing specialized equipment and more expertise to help.

The airport in the city of Valencia on Tuesday was crowded with aid groups from Japan and Spain along with Venezuelans returning from abroad. As a Japanese team exited the terminal with their search dogs, a crowd of Venezuelans at the airport applauded them.

In still another video a man pleaded for equipment after hearing hints of life beneath the rubble of a La Guaira apartment building. He said a mother and three children — an 8-month-old baby and two girls, 8 and 12 — remained trapped under unmovable concrete slabs.

Even where heavy machinery was available, experts cautioned that it could not always be used.

Excavators can destabilize damaged buildings and endanger trapped people, Mr. Hernández said. Instead, rescuers often rely on generators to power demolition hammers and grinders, cutting through concrete and rebar in a labor-intensive process that requires trained personnel.

“Everyone wants to do something, but nobody knows how to organize themselves or how to lead,” he said. “There is no order, there is no one giving us instructions.”

Volunteers have raised money to purchase generators, Starlink satellite terminals, demolition tools, flashlights and other equipment requested by Venezuelan and international rescue teams, said Mireya Fabrégas, who has coordinated donations from Venezuelans abroad.

Generators, she said, have been among the most urgently needed pieces of equipment to power rescue tools, lighting and access to the internet.

The Venezuelan government, facing criticism over the pace and capacity of its response, said it had dispatched more than 100 heavy machines to clear debris. But many volunteers say it is nowhere near what is needed.

“The government’s response is nil,” said Mr. Hernández. “Chaos reigns, anarchy reigns.”

At a collapsed building in La Guaira on Monday, investigators from Venezuela’s judicial police force triangulated the cellphone signals of two people believed to be alive under the rubble.

When a Qatari rescue team arrived with a search dog, rescuers called for silence. Motorcycles, buses and passing cars cut their engines as the dog searched. Minutes later, traffic resumed.

Andrea Parada, a surgeon whose relatives are believed to be trapped inside the building said rescuers first detected signs of life on Sunday.

“We know the days are passing, the hours are passing, time seems to move a bit faster each time, and our chances are running out,” she said. “But the aid that has arrived does not rule out the presence of life, and that’s why we keep trying.”

Patricia Sulbarán, Luis Ferré-Sadurní and Julie Turkewitz contributed reporting.