At least 29 people have been killed and 1,006 injured, according to the Nepali government. Six more are reported dead in neighbouring India.
The shallow 7.3 quake hit 68 kilometres west of the Nepalese town Namche Bazar, which is close to Mt Everest.
Nepalese patients are carried out of a hospital building following the 7.4 magnitude earthquake. Photo: AFP
The epicentre of earthquake was 83km east of Kathmandu, in a rural area close to the Chinese border.
Five died in Sindhupalchowk, the district to the east of Kathmandu that reported the most deaths in the April 25 shaker, district administrator Krishna Gwayali said.
He said the deaths were on a highway towards Tibet.
Six more were killed in Dolakha district close to the epicentre, an eyewitness said, adding that rescuers were trying to reach three people trapped in a house.
In the capital three people died, a police official said.
In neighbouring India, six people were killed when buildings collapsed.
One man was killed by falling rocks in Chinese Tibet.
People flee into the streets after a magnitude 7.3 earthquake hit Nepal as the country recovers from last month's devastating earthquake. Photo: AFP
Indian hospital staff and bystanders attend to a resident who fainted as a tremor struck at Siliguri Hospital in Siliguri on May 12, 2015. Photo: AFP
The quake sent people in the capital Kathmandu rushing out on to the streets when it struck at 12.35 local time, according to reports.
The epicentre (marked by the star) of the 7.3 Nepal quake in relation to Kathmandu and Mt Everest. Photo: USGS
The latest tremor was felt as far away as the capital of India, Delhi, as well as Dhaka, the capital of Bangladesh.
Emergency Response Director for NetHope Gisli Olafsson tweeted that his colleagues in Chautara reported buildings collapsing and said that people were "bringing hurt loved ones into the Red Cross hospital".
Nepalese patients lie on stretchers following the quake. Photo: AFP
"This is a really big one," Prakash Shilpakar, the owner of a craft shop in Kathmandu, told the Reuters news agency.
It came just weeks after last month's devastating 7.8 magnitude quake which killed more than 8,000 people and destroyed hundreds of thousands of homes.
Our colleagues in Chautara report buildings collapsing there in the 7.1M aftershock #NepalQuake
— Gisli Olafsson (@gislio) May 12, 2015
#NepalQuake: Major 7.4 aftershock east of Chautara further destroys buildings. All @UNOCHA staff have been accounted for.
— UN OCHA Asia Pacific (@OCHAAsiaPac) May 12, 2015
Last month's quake was only 15km deep and shallower earthquakes are more likely to cause more damage at the surface.
The BBC's Yogita Limaye, who is with an aid convoy in Nepal, said the latest quake went on "for a pretty long time."
"The earth shook and it shook for a pretty long time.
"I can completely understand the sense of panic. We have been seeing tremors: it's been two and a half weeks since the first quake.
"But this one really felt like it went on for a really long time. People have been terrified."
The Mt Everest Base camp was evacuated after the April quake and the climbing season has been called off.
We're safe. Did feel the earth shake for quite a long time. Saw dust and stones flying off mountain near by.
— Yogita Limaye (@yogital) May 12, 2015
Still shaking in delhi
— Jason Burke (@burke_jason) May 12, 2015
-BBC/Reuters
