The International Committee of the Red Cross says a Palestinian prisoner on hunger strike in an Israeli jail is "at immediate risk" of death.
The ICRC said Friday that Mohammed Allaan is in dire condition, calling on Israeli authorities to allow his family a visit.
"His family has been unable to visit him since 22 March, and they are very anxious about him. Given the current circumstances, we ask the Israeli authorities to allow them to see him as a matter of urgency," said the head of the ICRC delegation to the occupied Palestinian territories, Jacques de Maio.
Palestinian prisoners in Israeli jails regularly go on hunger strike to protest the harsh conditions in prison.
Last month, Israeli officials were forced to free another Palestinian prisoner, Khader Adnan, after his 56-day hunger strike brought him near death.
Adnan had been imprisoned for about a year without charge or trial.
More than 7,000 Palestinians are estimated to be imprisoned in Israeli jails and detention centers, many of them without charge or trial.
Last week, the Israeli Knesset (parliament) passed a law that prisoners on hunger strike were to be force-fed through tubes inserted through their nasal cavity.
The move has been met with local and international condemnation, with critics describing the act as a form of torture.