The gas explosion had occurred on Tuesday evening at a coal mine in Louxia Township of Pu'an County and had left 10 dead and five injured.
Authorities today found bodies of three people, who were previously reported missing, taking the death toll to 13, state-run Xinhua news agency reported.
The rescue operation has been wrapped up now.
China, the world's largest producer of coal, is grappling to improve standards in the sector, where regulations are often violated.