The latest outbreak, reported on July 28, left 84 people hospitalised after eating banh mi from a street food outlet in Nam Ban Lam Ha Commune, according to the provincial health department.
The order follows another outbreak in December 2025, when 97 people fell ill after eating banh mi purchased from a street vendor in Phan Thiet Ward.
Authorities have instructed health officials to investigate the latest incident, strengthen food safety monitoring and ensure prompt treatment for affected patients.
They also ordered inspections of all street food businesses, particularly banh mi stalls and mobile vendors, and food safety training for vendors.
The province said it would step up inspections of food ingredients and supply chains, while businesses found violating food safety regulations would face strict penalties and have their names made public.