The quake struck Wushi county, also known as Uqturpan county, in Aksu prefecture near the Kyrgyzstan border shortly after 2 a.m. local time, state-run news agency Xinhua reported.
Strong tremors caused two houses to collapse and downed two major power lines near the epicenter, though electricity was quickly restored, according to Xinhua.
The Xinjiang railway authority immediately sealed off routes in areas affected by the quake and suspended 27 trains, Xinhua reported.
Three people were hospitalized in a township 26 kilometers (16 miles) from the epicenter, state broadcaster CCTV reported. A child was rescued from the rubble of their house in that township, the broadcaster said.
Nearly 200 rescue workers have been dispatched to the quake zone, and hundreds more are being assembled, Xinhua reported.
More than 50 aftershocks above magnitude 3 were reported as of 11 a.m. Tuesday, according to the state-run China Earthquake Networks Center.
The quake’s epicenter is a remote, mountainous and sparsely populated area at an altitude above 3,000 meters (9,842 feet), CCTV said.
Five villages are located within a radius of 20 kilometers from the epicenter, which is about 50 kilometers from Wushi county’s main urban area, Xinhua reported.
Wushi county has a population of 205,000 people, according to China’s latest census in 2020.
Heavy tremors were felt in cities hundreds of miles away, including the Silk Road oasis of Kashgar and Hotan in southern Xinjiang.
Videos posted by Xinjiang residents on Chinese social media show lights swinging and crashing onto the floor, and crowds taking shelter outside in the streets, wrapped in winter jackets and blankets as overnight temperatures dropped as low as -10 degrees Celsius (14 degrees Fahrenheit).
The tremors were also felt across the border in Kyrgyzstan, according to the United States Geological Survey.
In nearby Kazakhstan, at least 44 people were injured in the country’s largest city Almaty following the quake, authorities said Tuesday. The quake was also felt as far away as Uzbekistan, Reuters reported.
Residents in the rural areas of southern and western Xinjiang are mostly Uyghurs, a predominantly Muslim ethnic minority that has been targeted by a sweeping Chinese government crackdown in recent years, from mass detention to strict restrictions on religious and cultural life.
A United Nations report said China committed “serious human rights violations” against Uyghurs that may amount to “crimes against humanity” – accusations that Beijing has vehemently denied.
In December, a powerful earthquake killed 151 people in the provinces of Gansu and Qinghai in northwest China, the deadliest quake to hit the country in nine years.
This story has been updated with additional details.
CNN’s Lucas Lilieholm, Mariya Knight and Wayne Chang contributed reporting.