A bad batch of raw oysters served March 20 at Travail Kitchen in Robbinsdale has prompted state health officials to warn consumers against eating a certain haul of the shellfish from Canada.

Twenty-nine Minnesotans were sickened with norovirus gastroenteritis after eating Stellar Bay Gold oysters that had been harvested 10 days earlier in Canada, health officials said Friday. The oysters were from Deep Bay 14-8 in British Columbia.

"Travail Kitchen quickly brought the cases to our attention and immediately stopped serving oysters," said Duane Hudson, Hennepin County Public Health Department's environmental health manager. "We are grateful to Travail for their help in protecting the public from foodborne illnesses."

The state Health Department, Hennepin County Public Health and the state Agriculture Department are working with federal officials and agencies in other states and Canada to investigate other illnesses associated with oysters harvested from Bay 14-8.

Officials said it's likely that oysters from this area are still in the marketplace. They're urging restaurants and distributors to check "shellstock" tags and discard oysters from this harvest area. Consumers can also ask oyster suppliers or restaurants to check for the harvest location.

Symptoms of norovirus typically include nausea, vomiting, diarrhea or stomach cramps that begin 12 to 48 hours after ingestion of the virus. Norovirus and other pathogens found in raw oysters can be destroyed by cooking to 145 degrees Fahrenheit before eating.