At least three persons were killed and 14 others injured in a bomb blast that hit a van carrying prisoners outside a prison in Johannesburg on Monday, local media reported.



An explosive device was triggered on a vehicle outside the Johannesburg Central Prison, the South African Press Association reported.

The vehicle was carrying about 36 prisoners as the explosion took place, which left three persons dead, four critically injured and ten others with light hurt, said the News24 on its website.

Police said it was caused by an escape plot planned by the "dangerous criminals" and the uninjured prisoners had been taken back to prison.

The preliminary investigation by police showed that the explosive device was hidden in the back of the vehicle, but it was not clear as to who executed the plot.