Schools, banks and businesses across the West Bank were closed on Thursday as Palestinians observed a general strike in solidarity with more than 1,500 prisoners on hunger strike in Israeli jails.

Public transportation came to a halt, and public and private institutions, including universities, were shut for the day.

Hundreds of Palestinian prisoners declared an indefinite hunger strike last week to protest grievances, including medical negligence, administrative detention and limited family visits.

About 6,500 Palestinians are currently in Israeli jails, 500 of them held under administrative detention.

Groups working to support the prisoners in their hunger strike also declared Friday to be a "day of rage", in which Palestinians were called on to confront Israeli soldiers at various contact points.

The strike was called by imprisoned Fatah party leader Marwan Barghouti, who is serving five life terms for his involvement in the Second Intifada against the Israeli occupation.

Barghouti launched the hunger strike on April 17. Those taking part in the hunger strike are ingesting only water and salt.

At a protest camp near the Old City in Ramallah, dozens of young men sat on plastic chairs surrounded by images of prisoners on strike as loudspeakers blasted songs about Palestinian detainees.

Holding a bright yellow Fatah flag, 26 year-old Ibrahim al-Rashidi said he had joined the strike for personal and political reasons.

"My cousin is on hunger strike. He has been in prison for 13 years," Rashidi told Al Jazeera.

"I want to send a message that I am with the prisoners. All the Palestinian people are with the prisoners. It will give the prisoners power and strength after they see the support they have."

Al Jazeera's Harry Fawcett, reporting from Ramallah, said almost every business and shop was shuttered in the occupied territories.

President Mahmoud Abbas' Fatah Party - the ruling party of the Palestinian Authority in the occupied West Bank - announced Friday to be a "day of rage" and called on all Palestinians to "clash" with Israeli forces to express solidarity for the ongoing mass hunger strike, Palestinian Maan news agency reported.

Fatah called for Palestinians to express their unity by performing Friday prayers at the many solidarity tents that have already been set up across the West Bank.

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"The excessive practices of the Israeli occupation, particularly those of the Israel Prison Service," necessitated that "we clash with the occupier everywhere across our homeland," the official statement said.

Fatah called for the general strike to include "all aspects of daily life".

The statement said that Israel would be held responsible for the lives of all Palestinian prisoners and for "any unrest in the region that may emerge as a result of Israel's stubbornness and indifference toward these prisoners' demands," Maan reported.

Qadura Fares, head of the Palestinian Prisoners Club, said that the issue of prisoners' rights had helped breach political divisions in Palestinian society.

"All the Palestinians are united behind the prisoners in their hunger strike," Fares said.

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"It shows that today, the Palestinian people are united. All the factions, all the unions, everyone is showing his or her solidarity in the villages and the cities. The Palestinian national crisis had become very deep and there was a feeling that it was impossible to act together with a single voice.

"But today, the days before and the days that will come after, I believe that the Palestinian people will reach some important conclusions."

Letter to Red Cross

Arab League chief Ahmed Abul Gheit on Wednesday urged the International Committee of the Red Cross to intervene with Israeli authorities to halt their "abuse" of Palestinian prisoners.

Abul Gheit sent a letter to ICRC president Peter Maurer requesting "the committee (ICRC) urgently intervene with Israeli authorities to stop the various abuses being committed against those prisoners of war", the Arab League said.

Abul Gheit's letter is part of contacts "with international actors to stop violations against Palestinian prisoners of war in Israeli prisons", the League said in a statement.

He called for the ICRC to demand Israel "ensure treating Palestinian prisoners on hunger strike according to norms and standards set in international humanitarian law".

With additional reporting by Nigel Wilson: @nigelguywilson