Injured students are helped by ambulances after?a stampede left six?pupils dead?at Mingtong Elementary School in Kunming, Southwest China's Yunnan province, Sept 26, 2014. Lifenews, a Kunming-based newspaper, posted the photo on Sina Weibo, China's microblogging service.

Six students were killed and 26 injured in a stampede at a primary school in southwest China's Yunnan Province on Friday, local authorities said.

The accident happened at about 2:30 p.m. at Mingtong Primary School in Kunming, capital of Yunnan. The injured, two in serious condition, were sent to two hospitals.

According to Lu Jia, vice head of the Panlong District, the stampede occurred after a nap, when students were walking downstairs in the dormitory building.

A student told Xinhua several children were playing with a large cotton cushion, which tipped over on top of a group of small kids. Other children streaming past the site were unaware of the covered children and stepped on the cushion and children underneath, causing chaos.

Witnesses were too young to give more detailed accounts, and the accident is still under investigation.

Most of the victims were in grade one and two.

The school was cordoned off in the afternoon. Teachers sent text messages with their mobile phones to parents of other students, asking them to pick up their children.

Zhou Ning, a professor in education with the Yunnan Normal University, said that schools should pay more attention to safety education, and make sure all students know how to cope with emergencies.

Founded in 1955, Mingtong is located in Panlong District in downtown Kunming and is one of the best schools in the district.

Screenshot shows Beijing News quoting a witness as saying on Sina Weibo that?part of a building?had collapsed, but the newspaper said the allegation could not be confirmed.