Thirty-eight people, including 15 children in the Mekong Delta province of Soc Trang, were hospitalized with food poisoning symptoms after eating bread on Sunday.
Son Thanh Dien, who sold the baguettes to residents of Po Ta Pin Hamlet, said the breads were bought from another hamlet in the morning that day as usual.
However, several hours after eating the bread, many people started vomiting and complained of headaches, and were taken to the local hospital, Dien said.
Victims said it was likely that there were problems with the soy sauce, because only those who used the sauce had suffered the symptoms.
Related agencies have taken samples for testing. Most of the victims have recovered, local reports said.