Explosion and fire took place at a gas well in western China's Sichuan Province early Thursday morning, causing one missing and one slightly injured, said China National Petroleum Corporation (CNPC).

The fire was brought under control, and the company has sent a team of experts to investigate the cause of the accident, said the country's biggest oil and gas producer and the owner of the well. Company sources added that gas released in the accident did not contain hydrogen sulfide, which is a sort of toxic and inflammable gas.

Local residents that had been evacuated were returning home, said CNPC.