OSAKA -- Seven elderly patients at a hospital in Sakai, Osaka Prefecture, died between May 7 and Saturday after contracting serratia bacteria -- apparently inside the facility, officials said Monday.

Four men and three women at Mimihara General Hospital died of infections caused by the bacteria, Sakai city and hospital officials told a press conference.

The patients were admitted to the hospital between December and mid-June and apparently contracted the bacteria after being hospitalized, they said.