The relief operation in areas worst affected by Saturday's South Asian earthquake has been massively stepped up in a race to save survivors.
In Balakot, close to the epicentre in Pakistan, US helicopters have been used for the first time to ferry supplies.
But in outlying areas relief has yet to arrive. Residents told the BBC people were resorting to eating grass in order to survive.
At least 23,000 people have died, most in Pakistani-administered Kashmir.
A further estimated 50,000 people were injured in the 7.6-magnitude quake and four million people have been affected.
Mukhtar Ali Khan, a resident of Alai, a town in Mansehra district in Pakistan's Northwest Frontier Province, walked for 11 hours to seek help.
LARGE AID PLEDGES
World Bank: $20m
Asian Development Bank: $10m
South Korea: $3m
He told the BBC's Urdu service that there are bodies strewn all over the town and the survivors are starving and yet no help has arrived:
"There has been no government help and no help even from any non-governmental organisation... It is complete devastation, all communication links are destroyed, roads and houses are destroyed," he said.
"I have seen people eating grass.... People are dying of starvation."
It is a similar situation in Kohistan, also in the North West Frontier province, where resident Musharraf Khan told the BBC that many people had died and now those who had survived were looting shops in a hunt for supplies.
However, the Karakoram highway which links Pakistan with China through the northern areas, was re-opened on Wednesday following its closure five days ago due to landslides and mudslides.
It is expected that the government and the non-governmental organisations will now be able to bring in necessary relief material.
In Balakot relief is finally getting through and yet such is the scale of the disaster that the BBC's Andrew North says that five days after the earthquake struck thousands of injured people, many of whom have had to walk for days to seek help, are still waiting for medical treatment.
The doctors at the makeshift medical centre say the delay has meant that many of their wounds have become painfully infected.
"It's hard to imagine worse conditions in which to provide medical care - the clinic is just a few tents open to the elements and helicopters land frequently nearby sweeping dust over the doctors and patients," our correspondent says.
"When they get to this clinic all the doctors can do is give them first aid. They don't have the capacity to do any more except hope more helicopters will arrive in time to evacuate them," he adds.
US Secretary of State Condoleezza Rice is in the Pakistani capital Islamabad to assess the devastation.
Ms Rice, who is on a scheduled tour of Central Asia and Afghanistan, held talks with Prime Minister Shaukat Aziz and is expected to meet President Pervez Musharraf.
After her meeting with the prime minister, Ms Rice promised more US aid would be made available to Pakistan in this its "hour of need".
"We will be with you not just today but also tomorrow," she said, although she did not specify how much the aid would amount to.
Mr Aziz said that Pakistan had been pledged $350m in official aid and private donations so far.
In the Indian-administered part of Kashmir, the authorities say at least 1,400 people are now known to have died, but the number is expected to rise.
But there was a faint glimmer of hope for those still missing on Wednesday when in the town of Muzaffarabad a five-year-old girl and a 45-year-old woman were both rescued alive from two collapsed houses.