Police say several youngsters at a Texas preschool were injured "as a result of a science experiment” on Tuesday.
The incident took place at The Yellow School at Memorial Drive Presbyterian Church, the Memorial Villages Police Department said in a Tuesday Facebook post.
About 12 students were hurt, including 11 children who suffered burns and one child who was trampled, KTRK reported.
Six children were taken to a local hospital for burn injuries, David Foster, fire chief for the Village Fire Department, told the station.
Other children were released to parents who were "taking them to their own doctors," he said. Foster said the cause of the incident is being investigated.
There was "a flash from the chemicals that were mixed and caused the flame burns," he explained.
"All the parents of the students that were injured have been notified, the other students who attend the school at the church are fine," Memorial Villages police wrote on Facebook.
When asked about the type of injuries, Foster said: "I really can't say."
A school spokesman told KHOU the injuries didn't appear to be serious.
"The Yellow School is an early childhood program for children 3 years old through kindergarten," the church says on its website.