A chemical leak sickened 100 workers at a factory owned by Colombian apparel maker La Estrella, local press reported on Saturday, citing law enforcement officials.

The incident stemmed from a carbon monoxide gas leak, the officials said. Carbon monoxide is used at the plant, which makes trousers for export to the US.

The leak took place during the Saturday "graveyard shift" and 86 workers were taken to hospital after reporting symptoms of nausea, dizziness and headaches.

Local authorities are understood to be investigating the incident.

The factory is located 570 kilometers northeast of Medellin, Colombia's second-biggest city. Employing 4,200 workers, La Estrella's annual exports to the US total a reported US$37m.

By Ivan Castano.