Videos published by China's state broadcaster CCTV showed houses destroyed with walls torn apart.

Rescue workers waded through rubble strewn across the ruins in the aftermath of the earthquake, footage showed, while some gave locals thick blankets to keep warm.

Surveillance images published by CCTV showed people running through a store's aisles as shelves shook violently, sending objects like toys tumbling to the ground.

In the town of Lhatse, videos geolocated by AFP showed debris scattered in front of streetside eateries.

The powerful quake struck Dingri county with a magnitude of 6.8 near the border with Nepal at 9:05 am (0105 GMT), according to the China Earthquake Networks Center (CENC). The US Geological Survey reported the tremor as magnitude 7.1.

"Fifty-three people have been confirmed dead and 62 injured as of Tuesday noon, after a 6.8-magnitude earthquake jolted Dingri County in the city of Xigaze in Xizang Autonomous Region at 9:05 am Tuesday," Xinhua news agency said.

Over 1,000 houses have sustained varying degrees of damage, it added.

"Dingri county and its surrounding areas experienced very strong tremors, and many buildings near the epicentre have collapsed," state broadcaster CCTV said.

Chinese President Xi Jinping on Tuesday emphasised "the full-scale search and rescue efforts, minimizing casualties to the greatest extent possible, properly resettling affected residents, and ensuring their safety and warmth through the winter", CCTV added.

Xinhua said that "local authorities are reaching out to various townships in the county to assess the impact of the quake".

Temperatures in Dingri are around minus 8 degrees Celsius (17.6 degrees Fahrenheit) and will drop to minus 18 this evening, according to the China Meteorological Administration.

Disaster relief aid, including cotton tents, quilts and items for high-altitude and frigid areas, had been dispatched by central authorities to areas impacted by the quake, Xinhua said.

The high-altitude county in the Tibet region is home to around 62,000 people and situated on the Chinese side of Mount Everest.

While earthquakes are common in the region, Tuesday's quake was the most powerful recorded within a 200-kilometre radius in the last five years, the CENC added.

- 'Shook quite strongly' -

As well as Kathmandu, areas around Lobuche in Nepal in the high mountains near Everest were also rattled by the tremor and aftershocks.

"It shook quite strongly here, everyone is awake," said government official Jagat Prasad Bhusal in Nepal's Namche region, which lies nearer to Everest.

But no damage or deaths had been reported so far and security forces had been deployed, Nepali Home Minister spokesman Rishi Ram Tiwari said.

Nepal lies on a major geological faultline where the Indian tectonic plate pushes up into the Eurasian plate, forming the Himalayas, and earthquakes are a regular occurrence.

In 2015, nearly 9,000 people died and more than 22,000 were injured when a 7.8-magnitude quake struck Nepal, destroying more than half a million homes.

Some tremors were felt in Bihar state in India but no injuries were reported.

Three people were killed and dozens injured after a 7.0-magnitude earthquake struck along the mountainous China-Kyrgyzstan border in January last year.

A quake in December 2023 in northwest China killed 148 people and displaced thousands in Gansu province.

That quake was China's deadliest since 2014, when more than 600 people were killed in southwestern Yunnan province.

In the December 2023 earthquake, subzero temperatures made the aid operation launched in response even more challenging, with survivors huddled around outdoor fires to keep warm.