By Deepak Adhikari, Michael Vurens van Es and Kaamil Ahmed

KATHMANDU, Nepal 

As rescue operations shift towards remote regions of Nepal after Saturday's devastating earthquake, the death toll has climbed over 5,000 as rescuers continue to unearth victims.

More than 9,000 people have also been found injured since the quake, according to figures released by Nepali police on Tuesday, as emergency services workers continued to search the remains of collapsed buildings.

The U.N. said in an update published Monday night that an estimated 8 million people in 39 districts have been affected by the earthquake. 

It also reported that 1.4 million are in need of food aid and more than half of them were people living near the epicenter of the quake in poor quality rural housing. 

The home ministry's disaster response unit earlier reported that almost 2,000 houses have been completely destroyed in Nepal. The figure does not cover the destruction in remote areas, where villages have reportedly been almost entirely wiped out. 

The International Organization for Migration, which has previously assisted Nepal in disaster preparation, said the extent of the damage will become clear as they reach remote areas. 

"We know from aerial and satellite surveillance that whole towns have been flattened," said the organization's Nepal chief Maurizio Busatti.

The medical NGO Medecins Sans Frontieres said an initial aerial assessment of 65 villages showed the majority had been visibly damaged or destroyed. 

The group said it was assessing access to water and sanitation in camps in Kathmandu and nearby Bhaktapur, an issue which has become a key concern as thousands of people remain displaced.

“As people stay in the camps for a long time, we will have a crisis of sanitation there,” said Anu Gautham, Water, Sanitation and Hygiene cluster coordinator at UNICEF Kathmandu. “There will be issues of diarrhea and cholera and the likelihood is that there’ll be epidemics in the big camp areas."

Nepalis have remained on edge since Saturday's magnitude-7.8 quake destroyed buildings, ripped up roads and set off avalanches in the Himalayas, including one which tore through the Mount Everest base camp, killing at least 18 people. 

A further 72 people were also killed in India, according to India's home secretary L.C. Govak. Chinese state media reported 25 deaths in Tibet.

The international community has pledged millions of dollars in aid to Nepal and numerous governments -- including regional neighbors China, India and Pakistan -- have sent specialist search and rescue teams to aid the emergency response. 

Turkey also contributed to search and rescue efforts with specialist teams and sent emergency aid to Nepal. 

The earthquake, the worst to hit the Himalayan nation since 1934, destroyed many old buildings and ruptured roads while telephone and Internet communication was severely disrupted.

Kathmandu's old district, which was home to numerous protected historical sites, has been the worst hit according to officials.

Several historic temples have collapsed, including in the iconic Durbar Square. The historic 62-meter tall Dharahara tower in central Kathmandu, was also brought crashing down by the quake.