Updated

KADUNA, Nigeria (AP) — A chlorine gas leak led 300 people to fall ill in northern Nigeria after a welder cut into a tank of the noxious gas, Nigerian environmental officials said Sunday.

John Odey, a spokesman for Nigeria's Environmental Ministry, said the leak started Saturday afternoon in Kaduna. He said people became ill and passed out after breathing in the gas.

Odey said emergency services controlled the leak Sunday morning after soaking the tank in water.

Industrial disasters occur regularly in oil-rich Nigeria, Africa's most populous nation, either from carelessness, failing pipelines or theft. In 2008, an oil pipeline explosion in Lagos killed 100 people, while more than 400 people died in two similar explosions in the megacity in 2006.