Politicians were seen fleeing the parliament chamber mid-session as the building shaked violently and overhead lights cut out.
People in Kathmandu are “extremely scared” to return to buildings after a 7.3 magnitude earthquake shook Nepal, a doctor in the region said.
Dr Pranav Shetty, part of the International Medical Corps emergency response team in Nepal, said: “Everyone is still outside. The local people in Kathmandu are extremely scared to go back in for fear buildings may once again collapse.
“I see many families with young children sitting outside in the very hot sun. Hotel workers are passing out water and biscuits.
“Our team immediately went to Patan Hospital where we had already been providing medical care to offer their help. Another of our teams is doing a helicopter assessment. Aftershocks are continuing to rattle nerves.”
Today’s earthquake has thus far left at least four dead and hundreds injured.
The US Geological Survey said the quake had a magnitude of 7.3 on the Richter scale and struck 42 miles (68km) west of the town of Namche Bazaar, close to Mount Everest.
It was followed closely by at least six strong aftershocks. Shockwaves were felt as far away as the Indian capital, Delhi, and Dhaka, the capital of Bangladesh.
The full extent of casualties is unknown, with reports of collapsed buildings and some fatalities coming in from remote areas close to the epicentre.
At least four people were killed in the town of Chautara in Sindhupalchok district, north of Kathmandu, after several buildings collapsed and more than a dozen were injured in landslides. Sindhupalchok suffered the heaviest death toll in last month’s quake.
Two deaths have been reported in Bhimeswhar, in Dolakha district. There are also concerns over a large glacial lake called Tso Rolpa in Dolakha that is held back by a fragile natural dam.
The Nepalese Ministry of Home Affairs described a disaster in both Dolakha and Sindhupalchok. At least one four-storey building in Kathmandu has collapsed.
The earth also shook strongly across the Nepalese border in Tibet’s Jilong and Zhangmu regions.
At least half a million Nepalese are already without homes and living in makeshift camps or among the ruins of their houses.
Tuesday’s quake came from a depth of 11.5 miles, deeper than the 9.3 miles of the quake on 25 April. Deeper earthquakes tend to cause less damage at the surface.
At 7.3 magnitude, Tuesday’s quake was about a fifth as strong as April’s 7.8 quake.
There are fears of significant fatalities in regions closer to Everest, which lies in the north-east of the country.
The quake’s epicentre was close to Everest base camp, which was evacuated after an avalanche triggered by the 25 April quake killed 18 climbers. Mountaineering companies have called off their spring expeditions on the world’s tallest peak.
The latest disaster comes amid a humanitarian emergency in Nepal, with aid yet to reach many remote parts of the impoverished Himalayan nation after roads were wrecked by landslides.
The United Nations last week said it had received just US$22m of the US$415m it has appealed for as it called for aid contributions to be “dramatically ramped up”.
Rows were ongoing over the aid that had been sent, with western officials accusing the Nepalese government of trying to centralise its distribution, hampering efforts to reach those most in need.
Nepal’s government came under fire when it closed its only international airport because the runway was deteriorating under the arrival of so many large aircraft.
Compiled and edited from ITV and The Guardian reports