Photo/Illutration Lunch served at the Asaka No. 5 Elementary School on March 11. At bottom left is a plate of fried noodles. (Provided by the Asaka City Board of Education)

ASAKA, Saitama Prefecture--Fried noodles served for a school lunch here were so hard after being cooked that six children and a teacher chipped their teeth during the meal.

Three of the children were treated at hospital, while others complained of sore mouths, officials at the Asaka City Board of Education said March 13.

The incident took place at the Asaka No. 5 Elementary School on March 11.

When preparing the noodles, school cooks increased the volume to be fried together and extended the cooking time to about 10 minutes because the oil temperature was too low and they feared the meal might not be finished in time to serve during the lunch break.

Before plates of noodles were put before the children and teachers, the school's vice principal sampled the dish and gave it the thumbs-up despite thinking they were a little hard, education officials said.

The children who chipped their teeth were in the first- to fifth-grade.