The fire was started on Thursday morning and spread over 233 hectares (575 acres) in Yunnan Province, the official Xinhua News Agency reported, citing government sources.
The six boys blamed for the blaze were fifth-graders at a local primary school in Dali, a popular tourist city in an area inhabited by the Bai ethnic minority. The boys ran away when they saw the fire spread, and there were no casualties from the blaze, Xinhua said.