Tape used for crime scene investigation.
At least 20 pupils died after their minibus taxi was involved in an accident just after Bronkhorstspruit on Friday afternoon, the Gauteng education department said.
MEC Panyaza Lesufi was on the way to the scene, spokesperson Steve Mabona said in a statement.
Lesufi tweeted earlier that the vehicle had caught fire after the crash.
More information was not immediately available.