UN experts have expressed “grave concern” for the lives of imprisoned pro-Palestine activists on hunger strike in the U.K., reminding U.K. authorities of their responsibility to protect the health of the activists after reports of neglect.

The experts emphasized that the state has a “heightened, not diminished” responsibility to take care of people when they are on hunger strike. This means that the U.K. must ensure that activists have ready access to medical care if they need it, and that authorities must not take retaliatory actions against them.

“Hunger strike is often a measure of last resort by people who believe that their rights to protest and effective remedy have been exhausted,” the experts said.

The statement was signed by eight UN experts, including Gina Romero, UN special rapporteur on the rights to freedom of peaceful assembly; Irene Khan, UN special rapporteur on the right to freedom of opinion and expression; and Francesca Albanese, the UN special rapporteur on Palestinian rights.