Indonesian police are hunting 26 prisoners who escaped from a jail in restive Papua province on the weekend after most of their guards failed to report for duty, an official said Monday.

The prisoners including robbers and rapists used a rope to scale a four-metre (13-foot) outer wall at Abepura prison, Jayapura district, on Saturday, Abepura prison chief Liberti Sitinjak told AFP.

"I'm extremely embarrassed. Our officers are not disciplined. Only three of the seven guards turned up for duty that day," he said.

"The prison isn't properly secured... the wire fence separating the wall and building is damaged so the prisoners could run away easily."

He said more prisoners were "waiting their turn" to climb the wall when guards finally spotted them and put an end to the breakout.

Eighteen other inmates escaped from the same prison last month amid reports of a bitter rivalry between wardens over who should be running the jail.

Police have set up roadblocks around Jayapura and along the border with Papua New Guinea in a bid to catch the escapees.

"We're also carrying out an internal investigation to see if our officers were unprofessional and need to be expelled," Sitinjak said.

Indonesia's prison system is riddled with corruption, drug abuse and disease, according to independent monitors. Human rights experts say inmates in Papua, including political prisoners, are often abused and tortured.

Papua's ethnic Melanesian majority has waged a low-level separatist insurgency for decades but foreign reporters and aid workers are denied access to investigate claims of genocide and crimes against humanity.