Hundreds of Palestinians on hunger strike in Israeli jails said Friday they would shun vitamin supplements and prison clinics in an escalation of their mass protest against detention conditions. \"We swear we will not retreat. We are potential martyrs. Either we live in dignity or die,\" prisoner organizers said in a letter announcing the move and which was read out by Ismail Haniyeh, prime minister in the Gaza Strip, during a demonstration. Rights groups say around 2,000 prisoners are on hunger strike to demand improved conditions in Israeli custody, such as an end to solitary confinement and more family visits. Administrative detainees have also challenged Israel\'s policy of indefinite detention without charge. The fate of the hunger strikers has touched a raw nerve among Palestinians, with daily support rallies in the occupied West Bank and Gaza, and political leaders warning that Israel could face new violence should any prisoner die. Dozens of Palestinians have gone on hunger strikes in tents put up in solidarity in the West Bank and Gaza Strip, which witnessed daily heavy attendance by residents and visitors from Arab and foreign countries. Israel says all prisoners receive adequate medical attention, including in civilian hospitals if required. A Prisons Service spokeswoman said there was no immediate sign of the hunger strike being stepped up. \"As of now, I know that those who should be receiving extra care are receiving it,\" the spokeswoman, Sivan Weizman, said. Defending its so-called \"administrative detention\" policy, Israel says some cases cannot immediately be brought to open court for fear of exposing Palestinian intelligence sources that have cooperated with Israeli security organs against militants. Two inmates who helped launch the hunger strike, Bilal Diab and Thaer Halahla of Islamic Jihad, were in the 73rd day of their fast Friday. Anat Litvin of Physicians for Human Rights in Israel quoted Halahleh\'s doctor as saying his death could be imminent. \"What is very worrisome is the fact that he said that he doesn\'t want to be saved if something happens to him and he loses consciousness,\" Litvin said, adding that the Prisons Service\'s medical facilities might prove inadequate. \"They don\'t have the equipment, they don\'t have the expertise; constant follow-up that is very much needed is not available,\" she told Reuters Television in Tel Aviv.