The major quake was registered just after 2:00 am (1800 GMT Monday) at a depth of 13 kilometres in China's Xinjiang region, about 140 kilometres (85 miles) west of the city of Aksu.
Local authorities dispatched a team to the quake's epicentre, Beijing's Xinhua state news agency said, while around 800 people were on standby for any large disaster relief mission.
The health ministry in Kazakhstan said that 44 people suffering "various" injuries had sought medical help in the city of Almaty, the country's largest city.
Images posted on social media and by local news outlets showed citizens streaming outside following the quake.
In China's Akqi County, six people suffered injuries -- two of which were "serious" -- according to a Weibo post by a Xinjiang government media account.
A total of 47 buildings in the county collapsed, while a further 78 were damaged, the post said.
Two residential houses and livestock sheds collapsed in the area near the epicentre, in rural Wushi County, Xinhua reported, while electricity was temporarily knocked out.
Video circulating on Chinese social media showed household appliances crashing to the floor as wild shaking rocked homes.
More footage shared by state broadcaster CCTV showed firemen entering a damaged building with cracked walls and police helping an injured local.
Local TV channels in the Indian capital New Delhi reported strong tremors in the city, about 1,400 kilometres away.
One Aksu resident told Xinhua that people rushed outside for safety during the shaking despite the frigid early morning temperatures hovering around -10 degrees Celsius (14 degrees Fahrenheit).
Cao Yanglong, in the city on a business trip, told the state news agency that while on the 21st floor of a hotel, he felt like he was "going to be shaken out of bed".
People also fled their homes to seek refuge in the street in Kyrgyzstan's capital Bishkek, according to an AFP reporter, after the quake caused walls to shake and furniture to shift.
Bohobek Azhikeev, head of the Kyrgyz Ministry for Emergency Situations, said in a video message that "no casualties or damage have been registered" in the city.
Five villages are located within 20 kilometres of the epicentre, according to Xinhua, and a slew of small aftershocks followed in the area, with magnitudes as high as 5.5.
And on Tuesday morning the Kazakh seismological agency reported two new tremors of magnitude 5.2 and 5.3 around 10:00 local time (06:00 GMT) in the same area
The tremors were felt in Almaty, where schools were closed, according to an AFP correspondent.
Tuesday's earthquake came the day after a landslide buried dozens of people and killed at least eight in the southwest of China.
A December quake in the northwest of the country 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 earthquake, subzero temperatures made the aid operation launched in response even more challenging, with survivors huddled around outdoor fires to keep warm.