A "mass fainting" of garment workers in two Cambodian factories is being investigated by authorities in the country, according to local press.

The incident, involving 800 workers, happened at two plants supplying footwear to sporting goods company Puma, reported Reuters.

Workers at Universal Apparel (Cambodia) Co and Huey Chuen (Cambodia) Corp factories fell ill on Saturday night and Sunday morning, according to the report. It was unclear what caused the fainting.

Spokespeople for German-based Puma were not commenting when contacted by just-style at the time of writing.