LA GUAIRA, Venezuela (AP) — Tensions flared Saturday as desperation grew in Venezuela's state of La Guaira as rescuers and civilians searched for earthquake survivors and the death toll rose sharply to 1,430.

Venezuela's government said families reported at least 68,900 people missing, three days after the one-two punch of 7.2 and 7.5 magnitude earthquakes devastated the South American nation.

WATCH: Crews race to find survivors in mountains of rubble after Venezuela earthquakes

Venezuelans looking for loved ones and neighbors used shovels, heavy equipment, ropes and bare hands atop mounds of toppled concrete throughout La Guaira, one of the hardest-hit states. They were joined by a growing number of international rescue teams who began to climb through the rubble, offering a small glint of hope to anguished families.

Tensions peaked over what many Venezuelans viewed as an inadequate response by the government, whose soldiers, firefighters, police and military cadets were evidently underprepared to respond to the scope of the tragedy. Many felt every minute ticking away as they ran out of time to rescue people alive.

Frustration was amplified by efforts to project the image of a robust state response.

"There's a pile of bodies over there from last night. Newborn babies," said Mileidy Romero, who was among those searching in the seaside town of Caraballeada. "At 8 p.m. (yesterday) there were people alive down there, and they haven't bothered to rescue them. We've located several bodies, and they haven't helped us recover them either. What are they waiting for?"

Aid agencies consider the first 48 to 72 hours as crucial for retrieving people alive, though that can be extended if they have access to food and water. Venezuelan officials said 17 flights carrying more than 1,600 rescue team members had touched down by Saturday.

Tension mounts during rescue efforts

Acting President Delcy Rodríguez said on state television that more than 14,000 members of the military and police are patrolling the area, where access is now blocked and special permits are required to enter. But many in disaster zones said they had seen little of their government.

WATCH: Reporter in Caracas describes earthquake destruction and response in Venezuela

Some people climbed the remnants of buildings and cried out names, hoping for any proof of life. Dust coated coastal communities. In punishing heat, more people wore masks as the stench of decomposition spread. In other parts of La Guaira, teams unloaded stacks of bodies from white trucks onto the ground of a dirt hospital parking lot, where they were to be identified.

With the absence of hard hats, rescuers and civilians used motorcycle helmets as they searched piles of debris that were once people's belongings: Eddie Murphy and Nemo DVDs, a kitchen sink, mattresses and shoes.

Some, frustrated by the government's response, blocked an excavator from leaving the site of a collapse and pulled the operator from its cabin shortly after state workers took selfies in front of flattened buildings and left without helping. The ruling party's officials often take selfies to show participation in government-related events.

A few feet away, at least five bodies wrapped in blankets.

A member of the crowd, Yeison Marcano, said those searching had received some assistance from an investigations unit but neither police nor the National Guard helped.

"They came to eat arepas and take pictures to make it look like they were working," Marcano said. "They didn't even get their uniforms dirty like we have. We've been here for three days."

A minute later, a man tried to grab a firefighter, shouting and cursing. "Silence! Silence!" rescuers shouted as they tried to confirm whether someone was trapped alive.

Meanwhile, an older man was pulled from the rubble of a public housing building. Visibly disoriented, he begged a nurse for water. He fought with personnel who put him into a pickup truck, screaming, "My family! My family!"

The capital's main airport is badly damaged

The International Organization for Migration said over 6 million people could be affected, some 2 million in the capital, Caracas, alone.

Experts said the destruction was amplified by the quick succession of shallow quakes. For days, smaller aftershocks occasionally shook the capital, Caracas and areas hit by the quakes, including one measuring 4.8 on Saturday.

The disaster poses a huge challenge for Rodríguez, the former vice president who took office in January after the U.S. capture and removal of then-President Nicolás Maduro. Venezuela has been facing economic disarray for more than a decade, and many people reject the legitimacy of the political movement Rodríguez represents.

Search teams and foreign aid continued to arrive from Mexico, the U.S., Brazil, El Salvador, France and elsewhere.

On Saturday, Mexican rescue teams climbed over collapsed buildings and pushed their heads into holes in the pancaked concrete to search for signs of life, occasionally hearing movement.

"We're rescuers from the Mexican military, if there's anyone down there still alive, make noise or scream. Now!" one man shouted.

For many, the images of international aid teams arriving and climbing through the rubble alongside them offered a glimmer of hope. Yonahí Regalado has been calling out the names of her sister and 1-year-old nephew and godson since 1 a.m. the day after the earthquakes until aid workers began to arrive.

WATCH: Venezuela's earthquake response hindered by economic and political crises

"It doesn't matter who it is, whoever, whether it's family or somebody else. If there is anyone alive, let's get them out," she said, as helicopters circled overhead.

Simón Bolívar International Airport, which serves Caracas, was badly damaged. One runway was operational as U.S. teams worked to repair the crucial throughway, Jeremy Lewin, a senior State Department official in charge of foreign assistance, told reporters.

Lewin said the U.S. military would help coordinate flights to bring in search and rescue workers, mobile hospitals and supplies. He said a U.S. Navy transport ship was docked off the coast, ready to receive airlifted survivors in need of medical attention. Lewin said it is a "race against the clock" to find people injured in the quakes.

Janetsky reported from Mexico City. Associated Press journalists Juan Pablo Arraez and Matías Delacroix in La Guaira, Venezuela, Clara Preve in Buenos Aires, Argentina, and Ali Swenson in Washington contributed to this report.