A group representing terrorism victims is protesting a Spanish court's decision to release a cancer-stricken man convicted of crimes linked to the armed Basque separatist group ETA.

Around 100 members of the Victims of Terrorism Association marched Saturday to Zaballa prison in Nanclares de Oca — a town in the northern Spanish Basque region — to demonstrate against the release of Josu Uribetxeberria.

Uribetxeberria has been convicted of kidnappings and murder. A judge ruled in late August that he could be released to get treatment for cancer. Prosecutors are appealing that decision.

Uribetxeberria, who remains in custody, went on hunger strike several weeks ago. Around 100 fellow ETA prisoners then refused food to press for his release on humanitarian grounds.

It was unclear what sort of cancer is afflicting Uribetxeberria.