One week on from an earthquake that killed more than 6,700 people, Nepal ruled out finding more survivors buried in the ruins of Kathmandu Saturday despite relatives refusing to give up hope.

Two days after any signs of life had been detected among the mountains of rubble that litter the capital, the focus was shifting to reaching survivors in far-flung areas who have yet to receive relief supplies.

The UN children's fund UNICEF warned of a race against time to avert an outbreak of disease among the 1.7 million youngsters estimated to be living in the worst-hit areas, with monsoon rains just a few weeks away.

The 7.8-magnitude quake wreaked a trail of death and destruction when it erupted around midday last Saturday, reducing much of Kathmandu to rubble and even triggering a deadly avalanche on Mount Everest.

"It has already been one week since the disaster," home ministry spokesman Laxmi Prasad Dhakal told AFP.

"We are trying our best in rescue and relief work but now I don't think that there is any possibility of survivors under the rubble."

As well as updating the death toll to 6,621, Dhakal put the number of injured at 14,023. More than 100 were also killed in India and China.

While multiple teams of rescuers from more than 20 countries have been using sniffer dogs and heat-seeking equipment to find survivors in the rubble, no one has been pulled out alive since Thursday evening.

- Clinging to hope -

Nevertheless, relatives of those missing have refused to abandon hope.

"I believe he must still be trapped and will be rescued alive," said Suntali Tamang, whose husband Langte, 41, was believed to be in the same neighbourhood of Gongabu where the last survivors were found.

"I reached here three days ago after he went missing," she told AFP after travelling to Kathmandu from the family's home in the northeastern Dolakha district.

"He was the family's breadwinner and I am praying for him to be brought back safely."

The exact scale of the disaster was still to emerge, with the mountainous terrain in the vast Himalayan nation complicating the relief effort.

With relief workers still to reach many areas, it is likely to be some time before authorities come up with a comprehensive list of people missing but police said the task of compiling names had begun.

The list so far only contained 204 names, national spokesman Kamal Singh Bam told AFP, as relatives had only just started approaching authorities.

"We have only just begun to draw up the list, the number will obviously go up," added the spokesman.

The numbers of foreigners who have died was also unclear with around 1,000 EU citizens still unaccounted for in Nepal, according to diplomats.

- 'Nowhere to go' -

Tens of thousands of survivors have been living out in the open in Kathmandu in the week since the quake, having either lost their homes or fearful that aftershocks could bring teetering buildings to the ground.

"We are not living in this tent out of choice. We are here because we have nowhere to go," said Dhiraj Thakur who has been camped out for the last week in Tundikhel Maidan, an open area in the centre of the city.

"I have seven family members with me which includes my wife, my sister, nephew and my parents. The rented room where we were living in Kathmandu is now in ruins.

"Most of our stuff is lost and even the person for whom I used to work as a driver is dead, so I don't know where I will get the money for renting another room," said the 24-year-old.

Shambhu Thapa, who worked as a cook in a hotel before it was wrecked in the quake, had decided to move back to his home village with his wife and three children now that he had no means of supporting them in Kathmandu.

"Even our village home is damaged, but at least it is our own land," he said after another night out in the open.

Rameshwor Dangal, of Nepal's National Disaster Management Division, said many were waiting to receive aid supplies or else be airlifted to safety.

"In many areas people are not getting relief and it is natural that they are unhappy about it," he told AFP.

UN aid chief Valerie Amos on Saturday said she was extremely concerned that Nepal's customs authorities were slowing the delivery of aid.

Amos said she had reminded Prime Minister Sushil Koirala that Nepal had signed an agreement with the United Nations in 2007 that provides for simpler and faster customs clearance for relief aid in the event of a disaster.

"He has undertaken to ensure that happens, so I hope that from now we will see an improvement in those administrative issues," she told AFP.

In Sri Lanka, visiting US Secretary of State John Kerry said the United States had provided $22.5 million in aid relief to Nepal.

1,000 Europeans still missing after Nepal quake
Kathmandu, Nepal (AFP) May 1, 2015 - One thousand EU citizens are still unaccounted for in Nepal, diplomats said Friday, almost a week after a massive earthquake that has claimed more than 6,300 lives and left survivors desperate for aid.

The Europeans had mostly been climbing in the avalanche-hit Everest region and trekking in the remote Langtang range in the Himalayas near the epicentre of the quake that ripped up infrastructure and left tens of thousands homeless.

"They are missing but we don't know what their status is," EU ambassador to Nepal Rensje Teerink told reporters in the devastated capital Kathmandu, confirming that 12 EU citizens are known to have died so far.

Another EU official said on condition of anonymity that the majority were likely to be found safe, but given the difficulty of the terrain and poor communications, their whereabouts were currently unknown.

Concern over the missing underscores the mammoth task facing rescue and relief teams struggling to reach mountainous districts cut off by Nepal's deadliest quake in more than 80 years.

Desperate survivors living at ground zero have complained they felt abandoned to their fate after losing their loved ones and livelihoods in the disaster.

"The scale and devastation wreaked by the earthquake and the aftershocks would have challenged any government. The Nepal government is leading the response effort and has deployed its available resources," UN aid chief Valerie Amos told reporters Friday.

Amos added that while she was "heartened and encouraged" by the generosity shown by the international community, there was an urgent need to provide emergency shelter and basic goods and services as the monsoon season approaches.

"So many people have lost everything," she said.

While the rescue of two survivors reinvigorated the search for further signs of life in the ruins of Kathmandu, the Red Cross warned of "total devastation" in far-flung areas.

Six days on from the 7.8-magnitude quake, authorities put the number of dead in Nepal at 6,204 while around 100 more were killed in neighbouring India and China.

Eighteen were killed when a quake-triggered avalanche roared over Everest base camp where scores were gathered for the start of the climbing season.

The popular Langtang trekking route was also hit by an avalanche on Tuesday.

But the full extent of the destruction wrought by Saturday's quake was still emerging, especially in the Sindhupalchowk region, northeast of Kathmandu, where the sense of desperation was mounting.

- Collapsed hospital -

"One of our teams that returned from Chautara in Sindhupalchowk district reported that 90 percent of the homes are destroyed," said Jagan Chapagain, Asia head of the International Federation of Red Cross and Red Crescent Societies.

"The hospital has collapsed, and people are digging through the rubble with their hands in the hope that they might find family members who are still alive."

AFP journalists in another part of Sindhupalchowk saw utter devastation.

"Almost every house in my village is destroyed, and 20 people died. We lost our cattle and our sheep," said Kumar Ghorasainee, amid the ruins of his hometown of Melamchi.

The 33-year-old English teacher said the school had collapsed and there was nowhere for the children to go.

"No one has come to help us -- the cars and the aid trucks just drive by ... How will we manage now?"

In Melamchi, shops and restaurants were closed and streets were mainly deserted.

In nearby rice-farming communities, almost all the houses had been so severely damaged that they were no longer habitable, and locals were sleeping in makeshift tents.

Although international relief organisers say the operation to reach rural areas is intensifying, people in Melamchi had received nothing.

- 'No one stops' -

"We see the helicopters, we see the planes, but no one stops here," said 23-year-old farmer Shalik Ram Ghorasainee.

"We read the news about foreign aid... and we are hopeful. But in reality no one comes here, we are completely unknown," he added.

Ghorasainee described how one Japanese aid team driving past his village had spotted a local man collapsed by the side of the road. They stopped to give him two painkillers, and then drove on, he said.

Rescuers from more than 20 countries have been searching for survivors, working alongside Nepalese emergency teams.

French, Norwegian and Israeli rescuers took part in a successful operation to extract a woman late Thursday from the ruins of a building in Kathmandu, close to where a 15-year-old had earlier been pulled to safety.

After spending 10 hours trying to free Krishna Khadka, the rescuers greeted her emergence from the rubble with whoops of joy. A doctor told AFP on Friday that she remains in intensive care.

The earlier rescue of 15-year-old Pemba Tamang, who told AFP that he stayed alive by eating a jar of ghee (clarified butter), was hailed as a miracle by medics who said he had suffered only cuts and bruises.