The Bangkok Post reported Saturday that the workers have been with the Japanese company for less than a year, said Pongthai Musikapong of the Labor Protection and Welfare Office in Ayutthaya.

Company executives have promised severance pay for all the staff, he said.

Nikon set up its first factory in Thailand in 1990. There are 8,000 permanent staff and 4,000 subcontracting staff at its four factories, the newspaper said.