(Reuters) – U.S. federal health officials said on Tuesday an investigation is underway over a multi-state outbreak of Salmonella Newport infections linked to frozen ground tuna, which were imported into the United States by seafood retailer Jensen Tuna.

No deaths were reported so far, but seven people have been hospitalized, the U.S. Food and Drug Administration (FDA) said in a statement http://bit.ly/2VaoETq.

Thirteen people fell ill between January 8 and March 20 in seven states, according to the U.S. Centers for Disease Control and Prevention (CDC).

The states included Connecticut, Iowa, Illinois, Minnesota, North Dakota, New York and Washington, CDC said http://bit.ly/2V8BmSg.

Jensen Tuna issued a recall on Monday for frozen ground tuna imported from JK Fish of Vietnam.

The recall was for three lots of individually packaged one-pound bags and 20-pound boxes, according to federal officials, who advised restaurants and retailers not to serve or sell recalled frozen ground tuna from Jensen Tuna.

Salmonella is a bacteria that can cause serious and severe infections in children, frail or elderly people and others with weak immune system.

Last week, Caito Foods LLC, an Indianapolis food company, voluntarily recalled fresh cut melon produced at its facility after reports of nearly 100 illnesses tied to Salmonella contamination.

(Reporting by Kanishka Singh in Bengaluru, Editing by Sherry Jacob-Phillips)