ST. PAUL — The Minnesota Department of Health says two more cases of E. coli infection have been confirmed in the state.

The department said Thursday it has been able to interview 14 of the 15 cases. Through the interviews, investigators confirmed that 12 of the ill people ate at an Applebee’s restaurant in Minnesota between June 23 and June 29.

Officials say the number of Applebee’s restaurants where ill people reported eating is up to nine — two locations in Blaine, and one each in Duluth, Roseville, Willmar, Woodbury, Monticello, Bemidji and New Hope.

Investigators are still trying to identify what caused the illness.

Applebee’s says with approval from the Health Department, the restaurant chain voluntarily changed suppliers and will reintroduce Oriental chicken salad to the menu at its Minnesota restaurants Friday.