[JURIST] A group of five prisoners who were held in special segregation units in Scottish jails is suing the Scottish Prison Service. The segregation units are used to hold prisoners that cause problems within the mainstream jail. The group's lawyer will argue in a hearing Tuesday that being kept in the segregation units, where the prisoners are kept in solitary confinement for 23 hours a day, violates the prisoners' human rights. The group will also argue that the prison service was aware of the problems caused by segregation units but failed to act. In an interview with BBC Radio Scotland, lawyer Tony Kelly said that removing a prisoner from the mainstream prison to segregation units "represents a gross detriment." Kelly said that "the prisoner is locked in a cell by himself, in some cases slopping out, for 23 hours a day. When he does get out for one hour, he's in a concrete pen within the segregation unit that is very small and hung over by a wire mesh." Justice spokesman for the Scottish National Party Kenny MacAskill has said that although prisoners forfeit their liberty, "they are still entitled to be treated with some dignity and some respect," and questioned the treatment of prisoners. BBC News has more.