Minneapolis Cafe Barbette, a popular restaurant in the Uptown area of Minneapolis, closed voluntarily over the weekend after more than 20 reported cases of salmonella poisoning at the restaurant.

The city health department has not determined what caused the food poisoning, but the restaurant believes it is isolated to one batch of chilled soup. "It probably went bad between the pureeing and chilling," the controller said. He believes the cooler may not have been cool enough.

Like all Minneapolis restaurants, Cafe Barbette is inspected every year. In April, inspectors found five critical violations that were serious enough to warrant a warning letter. Among the violations was a cooler that was five degrees too hot and an ice machine that needed to be cleaned.

In a follow-up inspection three weeks later, all the violations were found to be corrected.

The restaurant will be closed until Wednesday.