"The authorities reported…16 inmates injured and one died. In addition, six relatives of prisoners who were carrying out their visits, were injured," the statement said, as quoted by El Universal on Wednesday.
Some Venezuelan media reports said that at least two people were killed by the blast and 27 others were wounded.
The explosion occurred on visiting day.
On August 4, five prisoners were killed and at least 30 wounded in a bomb attack on a prison in the Venezuelan city of Maracay.