OSAKA -- City health officials said Wednesday they are looking into the cause of a suspected dysentery outbreak at a kindergarten here after six pupils were confirmed suffering from the infection. An additional 37 teachers and pupils are believed to be infected.

Of the six pupils, three girls between the ages of 4 and 5 were hospitalized and are reported to be recovering after experiencing mild dysentery symptoms, including fever and diarrhea, the health officials said. The six began showing symptoms Saturday.

The kindergarten was shut down Wednesday to allow health officials to determine the cause and route of the infection. City officials will question the teachers and examine the kindergarten's meals and kitchen.

The city government was struck by a similar case of dysentery between 1998 and 1999, when 186 people in Nishinari Ward were diagnosed with the infection.