Rescuers are racing against time in Venezuela, three days after two powerful earthquakes struck, with at least 920 people confirmed dead and more than 51,000 still missing.

The twin, magnitude 7.2 and 7.5 quakes hit on Wednesday, devastating the coastal area around La Guaira, where authorities moved on Friday night to restrict access as traffic chaos began to hamper search efforts.

With a scarcity of government rescue teams, Venezuelans have become desperate in the hardest-hit areas, digging through rubble with their hands, with aid agencies warning the critical 72-hour survival window is closing fast.

Officials said anyone who wants to enter the area around La Guaira would now have to seek official permits, but provided few details of who would be allowed in.

People reported seeing few state rescue teams in the hardest-hit areas, despite authorities projecting an image of a robust government response.

“Each person saved is a miracle,” said Jorge Rodriguez, president of the National Assembly.

“We are not going to hide absolutely anything about the magnitude of this tragedy.”

Government forces distributed food and water to survivors in La Guaira, and acting President Delcy Rodriguez said her government was mounting a full response during these “critical hours for rescuing people alive”.

She welcomed the arrival of international rescuers and humanitarian aid.

Rodriguez said La Guaira had been “militarised” and more help was on the way, even as residents said it was just a fraction of what they needed.

Rodriguez, the former vice president, took office in January after the United States captured and removed then-President Nicolas Maduro.

Venezuela has been facing economic disarray for more than a decade, and many people reject the legitimacy of the political movement Rodriguez represents.

‘People are still terrified to re-enter what were their homes’

The number of dead was expected to climb, as people reported tens of thousands of missing on independent digital databases.

Those figures likely included people who have been incommunicado due to the lack of phone signals, and some reports may be duplicates.

The number of injured was more than 3,300 as of midday Friday, and authorities said they had rescued 243 people.

The International Organization for Migration (IOM) said up to 6.76 million people could be affected, some two million of them in Caracas alone.

“It is already clear that displacement will increase, as people seek safety,” IOM Director-General Amy Pope said in a statement. “A swift response is essential as we deliver life-saving assistance and support the people of Venezuela through the difficult days and months ahead.”

The destruction was amplified by the quick succession of shallow quakes, experts said.

Loyce Pace, the International Red Cross regional director for the Americas, said, “People are still terrified to re-enter what were their homes.”

Venezuelan authorities said on Saturday that 1,600 members of foreign rescue teams had arrived in the country to assist with search and rescue.

But speaking to Al Jazeera, Nicole Kast, the Venezuela director for the International Rescue Committee, said rescuers were already in “the final hours of the search and rescue operations, 72 hours is the window in which we hope to find people still alive.”

“Venezuela was already in a situation of humanitarian need, with limited resources within their civil protection services,” Kast said. “Even though international rescue teams are coming, there’s still a significant gap, and many people will likely remain under the rubble.”

Struggle to locate loved ones

Reporting from Chacao, one of the hardest hit areas in Venezuela’s capital, Caracas, Al Jazeera’s Noris Soto said hope of finding survivors has dwindled.

“As we can see, the labours of working, the labours of removing debris, are still ongoing with heavy machinery and drills,” Soto said.

“But the chances of finding survivors at this point, according to the rescuers, are nearly zero,” she said.

She added that severed mobile and internet connectivity, particularly in La Guaira state, has made it difficult for many people to locate loved ones.

“The organisation has been so poor that the people, the citizens, are denouncing that they don’t even know where their relatives, their survivors are, or even where the bodies that have been found are being taken,” she said. (Al Jazeera)