A Palestinian former minister, Hamas member Wasfi Kabha, released on the fourth day of the hunger strike, said on Facebook that Barghouti had told him "the strike aims to achieve more humane, fairer and more dignified prison conditions".
General strike held in solidarity with hunger striking prisoners as Fatah party calls for "day of rage" on Friday.
Media Committee of Freedom and Dignity collective hunger strike confirmed that the health condition of Barghouti has severally deteriorated.
Palestinian supporters of the prisoners have called for a general strike across Palestine on April 27, followed by a "day of rage" against Israeli occupation forces on April 28.
Israeli authorities deal with the PA on electrical and fuel supplies for Gaza because Israel does not engage with Hamas, which it regards as a terrorist organisation.
A senior United Nations official expressed concern about the deteriorating energy situation in Gaza and called for swift action by Israeli and Palestinian Authorities and the worldwide community to ensure basic services keep running.More news: Arsenal constantly defy expectations so is FA cup coming home?
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"The excessive practices of the Israeli occupation, particularly those of the Israel Prison Service" require that "we clash with the occupier everywhere across our homeland", the Fatah movement said in its announcement of the mobilization on April 22.
Qadoura Fares, who runs the Prisoners' Club advocacy group, said Thursday's strike "reflects the large public concern" for the prisoners. Protesters blocked roads in the city with rocks and tires.
The hunger strikers are now only ingesting water and salt and are protesting for better living conditions, including better medical care and access to telephones.
The hunger strike is being led by Palestinian leader and prominent prisoner Marwan Barghouti, serving five life sentences over his role in the second Palestinian intifada, or uprising, of 2000 to 2005. On Thursday, the World Bank issued a report ahead of a conference of nations that contribute to the Palestinian Authority that concluded fuel shortages and insufficient infrastructure are creating a humanitarian crisis in the Gaza Strip.
Barghouthi is popular among Palestinians, with polls suggesting he could win the Palestinian presidency.
-The administration of the Prison Service impose punitive measures to confront the striking detainees, especially the leaders of the strike, including: moving the striking detainees and isolating them, confiscating their belongings, depriving them from watching TV, reducing the time of their break and depriving them from the canteen.