Humanitarian volunteers and emergency service crews from the UK have begun a search and rescue mission in Nepal, following the earthquake which left more than 3,500 dead and thousands of others injured.
Communication problems in the worst-affected areas mean families and friends around the world are still anxiously waiting for news of their loved one, with dozens of British and Irish people among those missing.
Those in the Nepalese capital described the impact of the quake.
Nicholas Roxburgh, a 26-year-old PhD student from Ormskirk, Lancashire, described running into the bathroom and finding an exit as soon as possible, before making his way to the street.
Mr Roxburgh, who lived in Nepal for nine months, said he had been sitting at his desk when the building began to sway.
He said: “Just a few doors down from the building where I had been staying, a hospital stood - relatively undamaged, its staff out on the street fearing collapse. Within minutes injured people began to arrive, in cars, taxis, on foot, being carried by others.
“It was immediately clear there had been casualties. The lifeless bodies of two young children were carried in, while countless others arrived with a variety of horrific injuries - many having been hurt by falling masonry, others having been pulled from collapsed buildings.”
Tales of escape have begun to emerge from quake survivors, despite widespread disruption to communication lines in Nepal.
Cystic fibrosis sufferer Nick Talbot, who was climbing the world’s highest peak, tweeted to let his followers know he was safe.
The 38-year-old, from County Durham, said: “Tough 48 hours after earthquake tsunami of snow, rock and ice hit base camp. Bruised, battered & lucky to be here, thx for all the kind msgs.”
Several Britons are thought to be stranded on Mount Everest, with access to its base camp cut off.
Climber Alex Staniforth, 19, from Chester, said he is “emotionally trashed” and “very lucky to be alive” after being evacuated to base camp.
Footage has also emerged online of the terrifying moment the avalanche stormed towards base camp, smothering it in a blanket of ice and snow.
The Foreign Office said it had not received reports of any Britons being killed or injured but embassy staff had assisted 200 people.
A total of 90 British and Irish-born people are among the missing, according to a website set up for the families by the International Committee of the Red Cross.
The 7.8-magnitude quake struck just before midday on Saturday, sending tremors through the Kathmandu Valley and the nearby city of Pokhara.
The majority of deaths were reported in Nepal, with deaths also being confirmed in India, Tibet, Bangladesh and the Nepal-China border.
The quake also set in motion an avalanche which swept the face of Everest, killing at least 17 people and injuring 61, government officials said.
An RAF plane packed with supplies has been dispatched to the crisis zone, while charity workers, experts and fire fighters from across the UK have already begun the search for survivors. They took with them more than 11 tonnes of kit, including torches, axes, rope, search cameras, stretchers and tents.
Mike Adamson, chief executive of the British Red Cross said: “As the death toll continues to rise it is our absolute priority to continue the search and rescue operations and get aid to those left stranded.
“The Red Cross has been working in the Kathmandu valley for the last three years, informing communities of what to do in the event of an earthquake. But though many of the newer buildings have survived, the older infrastructure was not able to withstand the force of the earthquake.
“Our thoughts go out to all those affected and we urge people to give to our emergency appeal to support Red Cross staff and volunteers to respond.”
Some 67 fire fighters from the International Search and Rescue Team (UKISAR) are among those helping.
The team will be able to provide specialised, technical search and rescue assistance in collapsed structures. This will include locating and rescuing people, canine support, medical teams, engineering, assessing the damage and stabilising scenes.
Spokesman Roy Wilsher said: “Our team is well on its way to Nepal and they will be using their specialist equipment, skills and knowledge in a bid to help locate and rescue people affected in Nepal.
“The earthquake has devastated Nepal and we want to ensure we are doing everything we can to help. The team which has gone out are all highly trained professionals who will be offering as much assistance in the rescue endeavour on the ground as they possibly can.”
Emergency services in Nepal said some 3,617 people have now died in the disaster, with many thousands more injured.
In a message to Nepalese president Ram Baran Yadav the Queen said she was “shocked to hear of the appalling loss of life and injuries” caused by the earthquake in Nepal, adding that her “thoughts and prayers are with the victims”.
Anyone who is caught up in the incident or worried about a family member should call the Foreign and Commonwealth Office on +44 (0) 207 008 0000.