The explosion occurred at around 10 am (local time) in the town of Shazi, Qinglong County. The injured, including four in critical condition, have been sent to hospital for treatment, according to rescuers.
Days of heavy rain triggered a landslide, which crushed the pipeline operated by the China National Petroleum Corporation (CNPC) and caused gas leak and ensuing blast, state-run Xinhua news agency reported.
The fire caused by the explosion was put out and residents nearby were evacuated, while further investigation continues.