At least three people were killed, hundreds were injured and 120,000 were evacuated after a powerful earthquake struck in southwest China on Sunday.

The quake had a preliminary magnitude of 6.2 and struck in Yunnan province, about 2,365 kilometres southwest of Beijing, according to the U.S. Geological Survey.

According to reports from the state-controlled Xinhua News Agency, 290 were injured, 15 seriously.

One of those killed was a five-year-old boy who was crushed by debris. The boy's parents were also trapped by debris, but were rescued by locals, the news agency reports.

The quake was followed by at least 233 aftershocks Sunday, according to the local seismological bureau. The strongest aftershock had a magnitude of 5.1, The Associated Press reports.

The evacuation of the more than 120,000 residents was ordered after officials deemed the tremor had made buildings unsafe. Even the seismological bureau's walls were cracked, an official with the bureau told AP.

Though roads, water and electricity did not seem to have been affected, several homes collapsed outright and the area's communications network was damaged, Xinhua reported.

Emergency relief agencies were rushing to the area, AP reports.

The epicentre of the quake was near Pu'er City, in southwest Yunnan province. Earthquakes are common in the region of China that borders with Vietnam, Laos and Myanmar. Since 1990, there have been more than 20 quakes with magnitude greater than 5.0, according to Xinhua.

With files from The Associated Press