Three schools in southwestern China's Chongqing Municipality had reported 27 confirmed A/H1N1 flu cases by 9:00 a.m. Sunday, according to the local health authorities.

No serious or death cases was involved, the emergency office of the municipal health bureau said.

The cases included 15 at the Fengdu branch of Southwest University, which has six senior high school classes, nine at Xichan Primary School in Dazu county and three at Xinli Central School of Zhongxian county.

The Xichan Primary School has been closed, Xinlin Central Primary School had suspended classes for grades involved and the Fengdu branch of Southwest University has been put under quarantine.

In a related development, by Saturday 31 people were confirmed to have contracted A/H1N1 flu at three universities in the development zone of Longfang city, northern China's Hebei Province, according to the provincial health department.

A/H1N1 flu outbreaks have also been reported at schools in other regions, such as provinces of Henan, Sichuan, Shaanxi, Shandong, Hunan and Jiangsu as well as Guangxi Zhuang Autonomous Region.

The Chinese mainland has reported 4,415 cases of A/H1N1 flu, of which 3,577 have recovered, the Health Ministry said Friday evening, adding the flu has so far caused no deaths on the mainland.

Globally, the disease has killed about 2,000 people and infected more than 180,000. It has spread to more than 170 countries.