Palestinian prisoners in Israeli jails have said they will declare a one-day hunger strike next week in solidarity with three other striking detainees.
Monday's strike has been called on behalf of Mahmoud Sarsak, Akram Rikhawi and Samer Al Bark.
The longest on hunger strike is 25-year-old Palestinian national footballer Sarsak - who has refused food for 82 days, followed by Rikhawi at 58 days and Al Bark at 19 days.
Anat Litvin, from Physicians for Human Rights Israel, said Sarsak and Rikhawi are in "very severe" condition. Israel's prison service says they are receiving proper care.
The upcoming hunger strike follows the mass strike of more than 2,000 prisoners which ended on May 14.
The strike was ended when Israel signed an agreement which pledged to “facilitate” the detainees’ demands. The demands included ending the policies of detention without charge or trial, and solitary confinement.
Despite this agreement, Sarsak has been held without charge or trial since he came to the West Bank from Gaza Strip to join the Palestinian national football team in 2009.
Rikhawi says Israel violated its pledge to release him when it extended his detention on May 21.
According to the Maan News Agency, based in Bethlehem, West Bank prisoner Dirar Abu Sisi is still being held in solitary confinement despite the agreement stipulating Israel would end that policy.
Amnesty International says that Israel has renewed at least 30 administrative detention orders and has issued at least three new ones since the deal was signed.