The victims were sent to Thai Binh provincial hospital and near-by Hoang An and Lam Hoa hospitals on June 2 after showing symptoms of food poisoning, such as stomachache and vomiting.
They were reported to have eaten dinner at their work place on June 1 before being hospitalised the next day.
Thai Binh provincial Department for Food Hygiene and Safety head Le Van Dien said poisoned workers purchased their meals at Dung Hop business, which was also attributed to a previous large-scale food poisoning case involving 160 workers from Phuc Khanh industrial zone in Thai Binh, in August 2012.
The cause of the suspected food poisoning is currently under investigation.
