It's not clear how the fire started & UJ says a computer lab has also been affected by the blaze.

JOHANNESBURG - The University of Johannesburg (UJ) has confirmed that its Sanlam Auditorium has been burnt down to the ground.

It's not yet clear how the fire started and the university has said in a tweet this morning that a computer laboratory has also been affected by the blaze.

#UJfire Spokesperson Herman Esterhuizen says there is no fire at the moment. It burnt down overnight. ML — EWN Reporter (@ewnreporter) May 16, 2016

Management is at the scene assessing the damage.

UJ says the auditorium at its Kingsway Campus was gutted overnight.

There's a heavy security presence at the entrance of the campus and only those with student cards are being allowed to enter the premises.

The building, which is believed to have contained computer labs, is no longer on fire, but is destroyed.

Management says it will be releasing a statement later with further details.