(CNN) -- A middle school in southern Florida was briefly placed on lockdown Wednesday while a hazardous materials team responded to reports of rashes on four students and a teacher.
The incident comes a week after another school in the district was also locked down after a series of rashes.
In Wednesday's incident, the team did not find anything in the classroom where the rashes broke out, but the four affected students were taken to the hospital as a precaution, Broward County School Board spokeswoman Marsy Smith said.
Lauderdale Lakes Middle School has 959 students, she said.
On May 16, a similar incident occurred at McArthur High School, which is in the same district. A dozen students and two teachers were taken to the hospital but released shortly afterward.
In that case, authorities concluded that the rashes were not infectious. The high school was tested for 160 chemicals, mold and mildew, but nothing was found, Smith said.
Officials do not know what caused the rashes at the middle school are and if they are related to the incident at the high school.
CNN's Kim Segal contributed to this report.