The International Committee of the Red Cross said on Saturday it is "extremely concerned" over the health of seven hunger-striking Palestinians held by Israel.
"The ICRC is particularly worried about Imad Abdelaziz Abdallah Al Batran, who has been on hunger strike for several weeks," the ICRC said in a statement.
Juan Pedro Schaerer, the head of the ICRC delegation in Israel and the Palestinian Authority territories, said Batran's life was at "immediate risk unless the detaining authorities find a prompt solution".
The Red Cross added any solution must take into account that detainees cannot be forced to eat or receive medical treatment.
According to the Palestinian Prisoners' Club, Batran, who was being held by Israel in administrative detention, has been refusing food since May 5.
Club spokesman Amani Sarahna told AFP Batran had been suffering medical conditions prior to his detention that had since worsened.
According to Sarahna, there are currently eight terrorist prisoners on hunger strike, some long-term prisoners and others detainees, including one who had recently began refusing food.
He said they were being held in Israeli hospitals and not prisons.