As Palestinian Muslims welcome the beginning of the month-long holy fast of Ramadan on Saturday evening, prisoner Ayman Tbeish enters his fifth month of hunger strike in protest against Israel’s Administrative Detention policy, in which prisoners are held indefinitely without charge or trial.The Palestinian Prisoners’ Center for Studies warned that Tbeish’s health condition was worsening, Ma’an News Agency has reported. The prisoner has low blood pressure, kidney problems, and is unable to stand.

Tbeish began his strike on February 28th. As his health deteriorated, he was moved to an Israeli hospital.

According to Rafat Hamdunah, director of the prisoners’ rights group, Ayman had been offered a deal to be released in January of 2015, should he end his strike.

He has, so far, rejected the deal.

Around 5,700 Palestinians are currently being held in Israeli jails, according to Ma’an, with nearly 300 being held under Administrative Detention.

Over 800,000 Palestinians have been detained since 1967, with 5,224 currently being held in Israeli prisons, by the PLO’s estimate.