MANCHESTER, N.H. — A norovirus sickened 18 people after a private function last month at a restaurant co-owned by a Democratic congressman that is popular with presidential candidates campaigning in the New Hampshire primary, state health officials said.

People who became ill attended the private function Nov. 24 at the Puritan Backroom conference center in Manchester, the state Department of Health and Human Services said Friday. One person later died, but it was unclear if the death was related to the norovirus outbreak, the department said.

The restaurant is co-owned by U.S. Rep. Chris Pappas and is famous for its chicken tenders. It has been in his family for more than a century and is a frequent stop for presidential candidates of both parties.

The nature of the event was not released, but it didn't appear that any current presidential candidates attended.

The manager of the Puritan Backroom, Erik Zink, said in a written statement that the restaurant's top priorities are promoting health and excellent food safety and that he was confident it was doing everything possible to maintain those practices.

Zink also said the restaurant had reached out to the family of the person who died to express “our condolences" for the death, which he blamed on unidentified causes.

After the outbreak, the Manchester Health Department conducted an inspection of the restaurant. Officials determined there was no ongoing norovirus risk to the public.

The symptoms of norovirus include diarrhea, vomiting, nausea and stomach pain, health officials said. The state sees 50 to 75 norovirus outbreaks every year.