BEIJING — An explosion at a gas plant in central China has killed at least 10 people and seriously injured others, the authorities said on Saturday. Five people were missing.

The explosion on Friday evening, in the city of Yima in Henan Province, sent a ball of fire and thick plumes of smoke into the air, according to local state media. The fire charred the factory building, leaving only the frame, the accounts said.

As the fire spread, nearby houses collapsed, and windows were shattered as far as two miles away, residents said.

The explosion occurred in the air separation unit of a factory owned by the Henan Coal Gas (Group) Co., according to Xinhua, the state-run news agency. No explanation was given for the explosion.