Beijing: Six people died and 28 fell ill from poison gas leaking at a fertiliser plant in southwest China, Xinhua news agency said on Friday.

Hydrogen sulphide leaked at the plant in Kunming, capital of Yunnan province, on Thursday, Xinhua said.

"The injured have received timely treatment and are in stable condition," it said, citing the local government.

The leak had been "effectively" contained and had not affected the surrounding environment, Xinhua said without elaborating.