Rescue work has resumed to find the victims and survivors of the latest deadly earthquake to hit Nepal.

At least 65 people died there and nearly 2,000 were hurt in Tuesday's 7.3 magnitude quake, with fears the figures could rise. At least 17 died in India.

The search continues for a missing US aid helicopter with eight on board.

Aid agencies have appealed for funding, saying Tuesday's tremor has badly hit efforts to help those already affected by the 7.8-magnitude quake on 25 April.

Thousands of Nepalis - many of whom have not returned to their homes since the first quake, which killed over 8,000 people - spent another night in the open.

The latest earthquake was centred about 76km (47 miles) east of the capital, Kathmandu, near the town of Namche Bazaar.

A second tremor of 6.3-magnitude hit 30 minutes later. Numerous aftershocks followed.

The main quake was felt as far away as northern India, Tibet and Bangladesh.

Nepal's districts of Dolakha and Sindhupalchowk, in the foothills of the Himalayas, were worst hit, with reports of landslides and fallen buildings.

The Red Cross said it had been told of many casualties in the town of Chautara in Sindhupalchowk, where it has a hospital and which has become a hub for humanitarian aid.

"Hundreds of people are pouring in. They are treating dozens for injuries and they have performed more than a dozen surgeries," said spokeswoman Nichola Jones on Tuesday.

Richard Ragan of the World Food Programme said the latest quake had set back the relief effort and many UN agencies were now "desperately short of funds".

Patients at the Teaching Hospital in Kathmandu were treated outside. Photo : AP

He said parts of Nepal were so hard to reach "that the images of how people are suffering in these remote places aren't so evident, but I can tell you... the devastation is tremendous".

A senior official in Dolakha made a similar appeal, saying more helicopters and supplies are needed to help those people stranded in remote villages.

"People are terrorised. Everyone is scared here. They spent the night in the open," said Prem Lal Lamichane.

Meanwhile, the hunt continues for a US Marine Corps Huey helicopter which went missing near the town of Charikot, in Dolakh, while delivering aid.

The Pentagon said six US Marines and two Nepali soldiers were on board.

Some 400 Nepalese soldiers backed by helicopters are now focusing their search on a nearby river, a senior Nepalese army officer said.

"The info we have is that it is down in one of the rivers, but none of the choppers has seen it yet," Major Rajan Dahal was quoted by Reuters news agency as saying.

The Pentagon had earlier said there had been no sign of a crash, and was hopeful the craft may have landed safely having indicated it had fuel problems.

While the major earthquakes of the last two weeks have brought down many buildings, others are badly damaged and remain a danger.

Officials walked through Chautura on Wednesday using bullhorns to warn residents to leave their homes. "

But most people had already left, spending the night in tents or or in makeshift shelters.

The question for many now is when to return.

"I was thinking of moving to a rented room, but today was so scary I can't risk my family's life," Dipak Koirala, in Kathmandu, told AFP news agency.