The health authorities are trying to find out where the students contracted the virus.

Fang Laiying, director of Beijing Municipal Health Bureau, said, "We can not change the status of Beijing's flu situation due to the current school outbreak. At present, there will be no adjustment to the preventative policies."

The flu outbreak has forced the school to start summer vacation a week ahead of schedule.

The primary school has 941 students and 78 teachers.

Meanwhile Beijing reported 21 confirmed A/H1N1 cases on Wednesday, the largest in a day. The new cases brings the total number in Beijing to 155.