It has been a grim start to the day for a Sebokeng school.

This is after an adminstration block at Khutlo Tharo secondary school was torched during the early hours of Wednesday morning.

Gauteng education MEC Panyaza Lesufi is expected to visit the school.

Police spokesperson Brigadier Mathapelo Peters said it was the caretaker at the school who alerted the police of the fire.

"We were alerted after 3am but we don't know what time the fire started. There was no one at the school when the fire started and the caretaker said he was also alerted by someone," Peters said.