The quake hit at 9:05 am local time with its epicentre located in Tingri, a rural county known as the northern gateway to the Everest region, at a depth of 10 km, according to the China Earthquake Networks Centre.
The US Geological Service put the quake's magnitude at 7.1.
Tuesday's epicentre was around 80 km north of Mount Everest, the world's highest mountain and a popular destination for climbers and trekkers. However there were no climbers in the area at the time.
More than 1,500 firefighters and rescue workers have been sent to the areas affected by the quake. (AP PHOTO)
Nepal's National Disaster Risk Reduction and Management Authority said the tremors were felt in seven hill districts bordering Tibet.
"So far we have not received any information of any loss of life and property," a spokesman Dizan Bhattarai told Reuters. "We have mobilised police, security forces and local authorities to collect information," he said.
Many villages in the Nepalese border area, which are sparsely populated, are remote and can only be reached by foot.
The impact of the quake was felt across the Shigatse region of Tibet, home to 800,000 people. The region is administered by Shigatse city, the traditional seat of the Panchen Lama, one of the most important figures in Tibetan Buddhism.
Residents ran from their houses in Kathmandu, some 400 km from the quake's epicentre. (AP PHOTO)
Chinese President Xi Jinping said all-out search and rescue efforts should be carried out to minimise casualties, properly resettle the affected people, and ensure a safe and warm winter.
More than 1,500 local firefighters and rescue workers have been dispatched to the affected areas, China's Xinhua news agency reported.
Some 22,000 items including cotton tents, cotton coats, quilts and folding beds have also been sent to the quake-hit region, it said.
Villages in Tingri, where the average elevation is around 4,000-5,000 metres reported strong shaking during the quake, which was followed by dozens of aftershocks with magnitudes of up to 4.4.
There are three townships and 27 villages within 20 km of the epicentre, with a total population of around 6,900, and more than 1,000 houses have been damaged, Xinhua reported.
Local government officials were liaising with nearby towns to gauge the impact of the quake and check for casualties, and the Everest region has been closed to tourists.
The Tingri tremor was caused by a rupture in what is known as the Lhasa block in an area under north-south compression and west-east stress, CCTV reported, citing Chinese experts.
Since 1950, there have been 21 earthquakes of magnitude 6 or above in the Lhasa block, the largest of which was the 6.9-magnitude quake in Mainling in 2017, according to CCTV.
Mainling is located in the lower reaches of Tibet's Yarlung Zangbo river where China is planning to build the world's largest hydropower dam.
A magnitude 7.8 tremor struck near Nepal's capital Kathmandu in 2015, killing about 9,000 people and injuring thousands in the country's worst ever earthquake. Among the dead were at least 18 people killed at the Mount Everest base camp when it was hit by an avalanche.
On Tuesday, tremors were felt in Kathmandu, some 400 km from the epicentre, and residents in the city ran out of their houses.
One person was injured when he jumped off the top of a house after feeling the strong tremors, Nepal Police spokesman Bishwa Adhikari said. The man was being treated in hospital.
The quake also jolted Thimphu, the capital of Bhutan, and the northern Indian state of Bihar which borders Nepal.
So far, no reports of any damage or loss to property have been received, officials in India and Bhutan said.
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