The four, all from Jenin in the West Bank, were arrested in a sweep, Ahlul Bayt News Agency reported.
Addameer, a prisoners' rights group, said Tuesday it was concerned about the health of three prisoners who have been on hunger strikes for weeks, the Egyptian news website bikyamasr.com reported.
One of the three, Ayman Shawarna, has refused all food and has drunk only water for 149 days, Ma'an News Agency said. He told Ma'an he is prepared to "intensify" his strike.
Shawarna is currently chained to a bed in a military hospital.
Samer Issawi, who has been on hunger strike for 118 days, stopped drinking water Nov. 21. Oday Keilani has been on hunger strike for 36 days.
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