Over 50,000 people have been relocated to safer locations after damage to buildings due a powerful earthquake of 6.8-magnitude that jolted Luding County in China's southwest Sichuan province which claimed the lives of 46 people.

As of Monday night, 16 people were missing and over 50 injured, Wang Feng, deputy director of the Sichuan provincial emergency management department told a media briefing in Chengdu.

Among the dead, 29 were from Ganzi Tibetan Autonomous Prefecture which administers Luding County, and the other 17 were from Ya'an City. Over 50,000 people in Ganzi and Ya'an have been evacuated to safety, the state-run Xinhua news agency reported.

The 6.8-magnitude earthquake jolted Luding County at 12:52 pm on Monday (Beijing Time), according to the China Earthquake Networks Center (CENC).

Sichuan has activated the highest level of emergency response for the earthquake.

The province had deployed over 6,500 rescuers, four helicopters and two unmanned aerial vehicles to the frontline.

"There were many aftershocks, and some roads were blocked. We had to climb over the debris to get to the town square of Moxi," a rescuer from the provincial forest fire brigade was quoted as saying to Xinhua.

Houses and infrastructure have been damaged to varying degrees, and some roads partially collapsed.

Electricity and communications in Moxi town had been cut, and emergency power-generation equipment was supplying electricity for residents taking shelter on the square.

Liu Fang, a local official, said that after the earthquake, she and other colleagues immediately evacuated the residents to the square about several hundred meters away.

According to the medics on the scene, after the earthquake, medical staff from the health centres in Moxi and neighbouring villages and townships responded immediately.

As of last night more than 50 slightly injured people had received treatment at a medical site on the square.

Special police rescue team had rescued more than 30 trapped people.

The Ministry of Finance and the Ministry of Emergency Management earmarked 50 million yuan (about USD 7.25 million) to support rescue and relief work. The provincial government also allocated 50 million yuan to Ganzi.

Relief supplies, including some 3,000 tents and 10,000 folding beds, were allocated to Luding County, where the epicentre was located.

Sichuan province is located adjacent to Tibet. The Tibetan plateau is known to be prone to heavy earthquakes as it sits right over the place where the tectonic Eurasian and Indian plates meet, often colliding with huge force.

More than 69,000 people were killed when an 8.2 quake struck the province in 2008 and a magnitude of 7 quake claimed 200 lives in 2013.

Monday's quake struck as the province is grappling with the rising number of COVID-19 cases.

Chengdu was under a snap lockdown due to a growing number of cases. Residents were told to stay home, with one person per household allowed out each day to buy necessities. Daily nucleic acid tests were also mandated until Wednesday, the Hong Kong-based South China Morning Post reported.

More than 1,000 cases have been reported since mid-August in Chengdu alone, a southwestern transport hub of 21 million people. Sichuan reported 105 new symptomatic cases on Monday and another 80 asymptomatic infections.

The province is also reeling under unprecedented drought and heatwaves persisted over vast swathes of China, with farmlands left dry after a month of no rainfall and little to no irrigation equipment available to farmers.