Four prisoners who absconded from Darwin's jail have been recaptured trying to sneak back into the prison a few hours later, in what the authorities have described as an "excursion".

Photo: 123rf.com

The minimum security prisoners were seen climbing a fence near low security, pre-release accommodation units shortly after the evening roll call at 7pm at the jail in Holtze, near Darwin, on Saturday.

They were found to be absent at a roll call after they were seen close to the boundary fence that surrounds the complex.

An alert issued on social media on Saturday night assured the public that the prisoners were not regarded as a threat.

The four men were seen trying to re-enter the facility shortly after 1am on Sunday.

In a statement, a spokesman for Northern Territory (NT) Correctional Services said it suspected the prisoners believed they could "leave and return to the facility unobserved and that their excursion outside the prison precinct would go undetected".

The four prisoners were rated as "open security", allowing them to leave the prison complex during weekday working hours for employment or voluntary work in the community.

NT Correctional Services Commissioner Mark Payne said the men have now been taken out of the pre-release unit and returned to the main prison.

- ABC