Updated

An official says at least 25 people were taken to the hospital after inhaling what was believed to be chlorine gas after a leak in the Kenyan capital of Nairobi.

Kenyan Red Cross officer Daniel Mutinda says more than 300 students at a nearby school were sickened by Wednesday's leak. Some of the victims fell unconscious.

Mutinda said officials were not entirely sure what the gas was but it was believed to be chlorine. The leak began after a man brought a drum containing gas to a scrap metal workshop in eastern Nairobi.

Police cordoned off the area.