BEIJING — A powerful earthquake that rocked a mountainous region of southwest China on Sunday killed at least 367 people and injured more than 1,800 others, according to the state news media. With dozens of people reported missing on Sunday night, the death toll was expected to rise.

The earthquake, which struck at 4:30 p.m. with a preliminary reported magnitude of 6.5, was centered in Ludian County in Yunnan Province but was also felt in two adjacent provinces, according to the official news agency Xinhua.

Residents reached by cellphone on Sunday night said that a series of aftershocks continued to jolt the region and that power remained cut off.

Initial news media reports said 12,000 homes had been destroyed and about 30,000 had been damaged, leaving tens of thousands of people homeless amid rainfall that was expected to continue for days. The main road leading to the most heavily affected area was initially blocked by a landslide but had been cleared by late Sunday, according to the state news media.