Hundreds of Chinese factory workers angry about new employment rules held their Japanese and Chinese managers hostage for a day and a half.
A statement from the Japanese parent company said the protest at Shanghai Shinmei Electric Company started last Friday morning and ended on Saturday night.
Shinmei Electric said 10 Japanese nationals and eight Chinese managers were held against their will at the Shanghai factory but were released uninjured after 300 police officers were called to the plant.
A security guard at the Shanghai factory said today that workers were protesting over new rules. He said they include workers only being allowed two minutes for a toilet break and being fined 50 yuan (£5) if they are late once and fired if late twice.