At least 45 people became ill after dining at a popular Waikiki restaurant at the International Market Place, state Department of Health officials said Friday. Some of the cases have been confirmed as the norovirus.

Herringbone Waikiki voluntarily closed Thursday due to the reported illnesses, and on Friday it had been cleaned, sanitized and cleared to reopen — although when it would begin to serve food again had not been determined.

Health Department spokeswoman Janice Okubo said inspectors from DOH’s Sanitation Branch cleared Herringbone to reopen Friday.

Herringbone spokeswoman Cassie Kim said the restaurant is reordering products after hundreds of pounds of food were discarded, including all stored produce and pre-made sauces.

“They had to throw everything away. They don’t have anything to serve,” Kim said.

Okubo said six patrons tested positive for norovirus. “There are others that are in the process for testing on Monday, and DOH may be collecting more stool specimens from others.”

Investigations are ongoing, Okubo added. “Potentially there are 45 cases total (29 customers and 16 employees).”

Herringbone’s marketing manager, Rob Mora, said in a statement: “The well-being of our guests is of paramount important to us and remains our absolute priority. We have worked closely with the DOH since the first reports of illness were received. We are grateful to them for their help and support.”

The Health Department received a call Monday from a person who reported becoming ill after dining at the restaurant with a group of people last weekend. The individual reported all five from the group became ill. An investigation was initiated when the department received additional calls from patrons who reported becoming ill after dining at the restaurant.

Food safety inspectors visited the restaurant Tuesday to investigate and collect samples, Okubo said. Health inspectors also went to the restaurant Thursday and returned Friday morning.

In a written statement, state epidemiologist Dr. Sarah Park said, “From what we know thus far, most likely this occurred via an ill food handler preparing food, although investigations are ongoing.”

Norovirus is a leading cause of illnesses from contaminated food, and infected employees are a frequent source of the outbreaks. Symptoms include vomiting, diarrhea and nausea. Overall, 1 out of 6 Americans get sick each year by consuming contaminated food or drinks, according to the Centers for Disease Control and Prevention.

“All staff undergo intensive training regarding hygiene, and compliance with DOH standards is constantly monitored,” Mora said.

The Associated Press contributed to this report.