Nepalese residents sit among the ruins of one of the three houses in the village of Kavre Wednesday which were left uninhabitable after a second major earthquake, measured at 7.3-magnitude, struck Nepal for a second time in three weeks on Tuesday. Photo: AFP

Ministries in Nepal battled Thursday to get aid to some of the remotest terrain on Earth, working from tents and makeshift shelters after an earthquake severely damaged government buildings in the capital.

Tuesday's deadly 7.3-magnitude quake triggered landslides and brought down buildings weakened by an even larger 7.8-magnitude tremor on April 25 that killed more than 8,000 people and destroyed nearly half a million homes.

Nepal's government, which admits to being overwhelmed by the scale of the April 25 disaster, is now racing to deliver relief to remote mountainous areas in the east of the country worst hit by the latest quake.

The difficulties have been compounded by extensive damage to the Singha Durbar government complex in Kathmandu, parts of which are now so unstable they can no longer be used.

The prime minister's spokesperson Uttar Kumar Khatri said even his team was now operating out of a tent, calling it a "difficult situation."

"Our operations right now are all focused on disaster management," he told AFP.

"We are now trying to see where everyone can be accommodated in buildings that are safe."

In Kathmandu, where 11 people died on Tuesday, many traumatised survivors spent another night outdoors, afraid to return to their houses.

Meanwhile, a major search operation resumed Thursday for a US military helicopter that disappeared with eight people on board while delivering aid to earthquake victims.

For a third straight day, US and Nepalese military helicopters and hundreds of ground troops scoured a remote mountainous area where the chopper went missing, underscoring the huge challenge of operating in the Himalayan country.

"We began searching early today with two army helicopters. About 400 troops have been deployed for this," Rajan Dahal of the Nepal Army told AFP by phone from eastern Dolakha district where the chopper disappeared.

With many of the worst-hit areas inaccessible by road, more than 1,400 people have been airlifted from quake-hit areas, most of them by Nepalese troops.

Home ministry spokesperson Laxmi Prasad Dhakal said the death toll from Tuesday's quake, which was centered 76 kilometers east of Kathmandu, had risen to 96 overnight with more than 2,500 wounded.