CHONGQING - More than 100 children from a kindergarten in Southwest China's Chongqing municipality have been hospitalized after unexplained petechiae were found on their lower limbs, local health authorities said Thursday.

So far, a total of 115 children from the Guji Kindergarten, in Changsha township of Kaixian county, have been taken to three local hospitals for treatment and observation, sources with the county's public health emergency response center said.

Blood and urine samples have been sent to Chongqing city and Beijing for tests.

Local health authorities carried out a thorough check of all of the roughly 300 children in the privately-owned kindergarten after some of them showed the symptoms on Wednesday.

All the hospitalized children are in stable condition. Among them, two are in relatively serious but not life-threatening condition, according to the sources.

Health experts have initially ruled out the possibility of contagion.

Health experts from local authorities as well as the National Health and Family Planning Commission have begun a coordinated investigation into the cause of the disease outbreak.