Teikyo University Hospital said Wednesday four more people have died among inpatients infected with Acinetobacter, an antibiotic-resistant bacteria, and it will not receive any new admissions for an indefinite period to prevent more infections.

The hospital in Itabashi Ward, Tokyo, said 53 inpatients have been infected, seven more than the 46 already announced. The hospital is currently looking into the cause of the deaths to determine whether Acinetobacter was to blame.

The Tokyo Metropolitan Government said Wednesday that a 76-year-old man who died of pneumonia in June at Tokyo Metropolitan Geriatric Hospital, also in Itabashi Ward, after being transferred in February from Teikyo University Hospital, was infected, and that two others at the Metropolitan Geriatric Hospital were also infected.