Authorities in Cambodia say a worker has died and 18 others have fainted at a garment factory in eastern Cambodia that has been closed pending an investigation.

District governor Duk Kanthor said five female workers fainted Thursday at the Or Sambath Trading factory after reporting symptoms of dizziness, vomiting and difficulty breathing.

They were sent to a hospital, where a 21-year-old worker later died, he said. On Friday, 15 more workers fainted after reporting similar symptoms, he said.

It was not immediately clear what caused the workers to faint, he said.

The garment industry is Cambodia's biggest export earner, employing about 700,000 people in more than 700 garment and shoe factories.