Now Prime Minister Peter O'Neill as called on Correctional services to explain how and why this occurred.
O'Neill has also announced a ban on all day temporary release of prisoners, except under exceptional circumstances, until a review of procedures is undertaken, and the enactment of stronger penalties for prisoners who escape custody as well as those who aide or harbour them.
"The escape of six prisoners on day release is intolerable and places communities at risk. Some of these prisoners have attempted escape in the past and should never have been allowed outside prison walls.
"We need the right balance in our correctional services so that when a person is given a jail sentence, that they have a chance to reform and re-enter society," O'Neill said.
"Day-release from prison and gradual re-entry into society is an important part of rehabilitation. But too often we hear of cases where prisoners are released back into the public without due concern for the welfare of the public."
O'Neill said this had to stop, adding that there would be exceptional circumstances, such as legitimate medical care.
Efforts to re-apprehend the escaped prisoners would be stepped up, and penalties for escaping or harbouring escapees would be increased, O'Neill said.