Landslides have forced people from the worst affected villages in Nepal to carry their injured out by foot in the aftermath of the devastating 7.8 earthquake.
The death toll, currently sitting around 5000, is expected to rise exponentially when rescuers make it to the isolated communities, some of which are thought to have been almost wiped out by Saturday's quake.
About 8 million people are estimated to have been affected and hospitals are stretched to breaking point.
International aid agency ChildFund has been focussing its efforts in the remote, hilly district of Sindhupalchowk, situated near the epicentre of the quake.
ChildFund New Zealand spokeswoman Kiri Carter said it was one of the most damaged areas with about 80 per cent of the houses destroyed.
The district's death toll was sitting at 1156 and more than 700 people have been injured.
Many villages had no access to medical care unless they could carry their loved ones nearer to Kathmandu on stretchers, she said.
"People are quite desperate. A quake hits and you can have a landslide, be buried by it, you can be cut off, anything.
"They've got no shelter, no food, no water, no medical aid, they're terrified of further shocks. But in this district the biggest problem is that even if people are outside, they're not safe. It's the threat of landslides."
Roads were in the process of being partially reopened with the help of the Nepalese Government but there were still a lot of communities completely cut off, she said.
Death toll numbers would go up substantially as rescuers trek to the district's most remote areas, she said.
"They've opened part of the roads and they're pretty much doing a continuous [death] count as they get further into the district.
"They're extremely difficult to reach. People are miles from each other so it's finding people and knowing what's happened to people that's the difficulty."
Oxfam New Zealand humanitarian project director Bert Maerten said accessibility to the remote villages was really constrained.
The organisation hasn't deployed anyone from New Zealand but was focussing on bringing clean water, toilets and shelter to the area, with its initial effort aimed at reaching 350,000 people.
It is working across four open air sites in the Kathmandu Valley and hopes to step that up to 16 sites before long, Mr Maerten said.
"Those communities are on steep slopes, mountainsides, that cover most of Nepal. It's challenging to connect with them, roads are often blocked by landslides. The Kathmandu airport is functioning but it's just too busy.
"Coordination [between agencies] is really critical at this point."
Unicef New Zealand executive director Vivien Maidaborn said aid organisations were facing devastating systematic issues at the same time as the immensely personal problems for the people of Nepal.
After the initial rescue response, the organisation was looking to set up safe playing areas and schools for children.
"The view is there's probably another 5000 bodies in the rubble. Children are just playing in that environment, that's what children naturally do. So we've got to create spaces where it's safe for kids to do that."
World Vision's Nepal operations manager Phillip Ewert said work was being carried out in an urgent manner by his team who were sleeping in tents.
Everyone was expecting the death toll to rise as efforts continue, he said.
"We know the clock is ticking for those impacted by the earthquake. Aid is a matter of life or death for many at this point," Mr Ewert said.
The New Zealand Red Cross has deployed three men for Kathmandu this week, taking more than 300kg of IT and telecommunications equipment with them.
Further New Zealand Red Cross aid workers will be deployed in coming days to assist with the response.
Foreign Minister Murray McCully today announced New Zealand will make a further contribution of $1 million to the Nepalese aid effort.
It would be used to support accredited New Zealand non-government organisations, with partners on the ground in Nepal, on a matched-funding basis, Mr McCully said.
"New Zealanders have been giving generously to the appeals established by aid agencies and the Government's commitment will help match this generosity dollar for dollar up to a value of $1 million.
"The extra funding brings our total contribution to date to $2 million, and it will allow aid agencies to scale up the distribution of relief items and early recovery work."
He added: "We remain committed to helping the people of Nepal in these difficult times and will continue to assess how we can assist further."
NEPAL IN NUMBERS:
Undetermined number missing
8 million affected, including 2.8 million children
940,000 children in need of urgent aid
1.4 million in need of food
35,000 homes damaged
5000 schools destroyed
70,000 people have left Kathmandu to search for relatives in remote areas
1000 climbers on Mount Everest when the first avalanche struck. Death toll has reached 17 with 61 injured and an unknown number missing.
World Vision: Nepal Earthquake Appeal worldvision.org.nz on 0800 90 5000
Unicef: Visit unicef.org.nz/nepal or call 0800 243 575
Oxfam: Visit oxfam.org.nz or call 0800 600 700
Red Cross: Visit redcross.org.nz or call 0800 Red Cross (0800 733 276)
ChildFund New Zealand: Visit childfund.org.nz/Nepal-Earthquake-Appeal or call 0800 808 822
Caritas Aotearoa New Zealand: Visit caritas.org.nz or call 0900 4 11 11
New Zealand Nepal Society: Donations can be made to bank account number 01-0142-0053378-00
Himalayan Trust Rebuild Appeal: Visit givealittle.co.nz/cause/nepalearthquake
Save the Children: Visit savethechildren.org.nz or called 0800 167 168
TEAR Fund: Visit TEAR fund.org.nz or call 0800 800 777