BETHLEHEM - Israeli prison authorities have enacted a series of new procedures to punish hunger strike action by prisoners, Hamas-affiliated detainees told Ma'an on Saturday.

Prison authorities have confiscated personal belongings from prisoners, conducted strip searches, and placed prisoners in small metal containers in Negev prisons in southern Israel.

Six prisoners were placed outside in the containers as a punishment, a letter from Hamas detainees said.

Authorities have also banned breaks for prisoners, it added, calling on human rights organizations to intervene.

On Friday, Hamas detainees said in a statement that the Negev prison administration isolated some 30 prisoners who are on hunger strike and confiscated their belongings in addition to other privileges.

Thousands of Palestinians are on hunger strike in Israeli jails, and several are at risk of death. They are protesting detention without trial, restrictive visiting rights and limited access to educational materials.

Human Rights Watch on Wednesday called on Israel to "immediately charge or release people jailed without charge or trial under so-called administrative detention."