Three prisoners suffered smoke inhalation after a fire was set in a Gisborne Police Station cell overnight.

Police say two prisoners who were in a cell together set fire to some bedding in the cell about 8.45pm on Saturday.

The Fire Service attended and quickly put the fire out. But three prisoners were taken to Gisborne Hospital suffering from smoke inhalation. They had no other injuries.

The cell was only smoke damaged. Four other prisoners in other cells have been moved to temporary accommodation.

Police have begun both a criminal investigation and an internal investigation into how the fire started.