11.  But they had not been able to pinpoint the specific food after hundreds of tests on food samples.

12.  But they have been unable to pinpoint the specific foods that spread it.

13.  Health Ministry official Yuichiro Ejima said school lunches are still suspected as the cause, and the search for the specific food would continue.

14.  Health officials believe tainted school lunches set off the Sakai outbreak mid-July but have been unable to pinpoint the specific foods.

15.  The current outbreak is blamed on contaminated school lunches, but officials have not been able to determine the specific food that contained the bacteria.

16.  The current outbreak in Japan has been blamed on contaminated school lunches, but officials there have not been able to determine the specific food that contained the bacteria.

17.  The Japanese city where thousands of children have fallen sick from food poisoning acknowledged Monday that the prospects for pinpointing the specific foods that caused the outbreak were bleak.

18.  The scientists participating in the conference stopped short of singling out specific foods which should be avoided.