The restaurant, Sushi King, remained closed yesterday after a salmonella outbreak.
Ann Wright, a spokeswoman with the Arkansas Department of Health and Human Services, said the department's lab has confirmed 30 cases.
The cases were connected to the restaurant because of statements given by people who became sick, but food taken from the restaurant tested negative for salmonella. Wright said the cause of the outbreak may never be known.
Sushi King owner John Wei voluntarily closed the restaurant while the Benton County unit of the Health Department completes its investigation.
Wei says he does not know when he will reopen the restaurant. All food in open containers must be thrown out, the restaurant must be sanitized, and employees must take classes on safe food handling.
He said it will be like opening a restaurant from scratch.