Caption:KATHMANDU, NEPAL - APRIL 25: Emergency rescue workers carry a victim on a stretcher after Dharara tower collapsed on April 25, 2015 in Kathmandu, Nepal. More than 100 people have died as tremors hit Nepal after an earthquake measuring 7.9 on the Richter scale caused buildings to collapse and avalanches to be triggered in the Himalayas. Authorities have warned that the death toll is likely to be much higher. (Photo by Omar Havana/Getty Images)
Omar Havana/Getty images
Caption:KATHMANDU, NEPAL - APRIL 25: Emergency rescue workers carry a victim on a stretcher after Dharara tower collapsed on April 25, 2015 in Kathmandu, Nepal. More than 100 people have died as tremors hit Nepal after an earthquake measuring 7.9 on the Richter scale caused buildings to collapse and avalanches to be triggered in the Himalayas. Authorities have warned that the death toll is likely to be much higher. (Photo by Omar Havana/Getty Images)
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In this Sunday, April 26, 2015, photo taken by Amul Thapa and provided by KathmanduToday.com, four-month-old baby boy Sonit Awal is held up by Nepalese Army soldiers after being rescued from the rubble of his house in Bhaktapur, Nepal, after Saturday's 7.8-magnitude earthquake shook the densely populated Kathmandu valley.  Thapa says that when he saw the baby alive after 20 hours of rescue efforts "... all my sorrow went. Everyone was clapping. It gave me energy and made me smile in spite of lots of pain hidden inside me." (Amul Thapa/KathmanduToday.com via AP)
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Story highlights

NEW: The disaster has affected 8 million people across Nepal, U.N. estimates

NEW: The death toll in Nepal alone has risen to 4,352, Home Ministry says

Four U.S. citizens now reported dead, State Department says

Editor’s Note: As the rescue and recovery efforts continue, many charities and NGOs are sending teams, aid and medical assistance. Click here to find out about the organizations you can assist.

(CNN) —  

Rescue and aid workers in Nepal are struggling to cope with the scale of the devastation dealt by Saturday’s powerful earthquake – digging through rubble by hand, performing surgeries in makeshift operating theaters, scouring notoriously difficult terrain for more victims.

But power blackouts in the capital city of Kathmandu, supply shortages and difficulties getting around complicated the efforts.

By Tuesday morning, more than 4,400 people were confirmed dead as a result of the earthquake, the overwhelming majority of them in Nepal. Over 8,000 people were reported to have suffered injuries.

The United Nations estimated that the disaster had affected 8 million people across the Himalayan nation. More than 1.4 million people are in need of food assistance, the world body said in a situation report Monday.

CNN’s Dr. Sanjay Gupta said doctors at one Kathmandu hospital had moved patients from the 120-year-old building and into another structure, where they were operating on patients in rooms normally not used as operating theaters.

Hospitals were running short on supplies despite international efforts to bring in aid. Numerous aid groups and at least 16 nations rushed aid and workers to Nepal, with more on the way.

And across the region, thousands prepared to spend another night outdoors, fearing that damaged buildings could collapse if there are more aftershocks.

The destruction in Kathmandu, the capital, is stark: revered temples reduced to rubble, people buried in the wreckage of their homes, hospitals short on medical supplies and overflowing with patients. Serious damage is also reported in villages in the surrounding valley.

Social media posts from Nepal

But farther out across Nepal’s rugged landscape – closer to the epicenter of Saturday’s magnitude-7.8 quake – the situation is disturbingly murky. </