Thousands of Palestinians rallied in the West Bank village of Arraba on Monday, on the eve of Palestinian Prisoners' Day.
The event on Tuesday will coincide with the release of Khader Adnan, an Islamic Jihad member who went on hunger strike for a record 66 days in protest at held by Israel without charge.
This year's Prisoners' Day will also mark the start of mass hunger strike by 1,600 Palestinians detained in Israeli jails, more than a third of the total, according to prisoners minister Issa Qaraqaa.
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The minister unveiled a huge fresco representing Palestinian prisoners at the entrance to Arraba, Adnan's home village in the northern West Bank, before a crowd of nearly 1,000 people.
"The celebrations on Prisoners' Day are different this year because the conditions of of Palestinians detained in Israeli prisons have worsened," Qaraqaa said in a speech.
"Our people will continue to struggle for the release of all the prisoners," he told the audience. "There will not be peace in the region without the liberation of all Palestinian prisoners."
Some 4,000 people from the West Bank as well as Israel gathered in the centre of the village waving photos of prisoners, of late Palestinian leader Yasser Arafat and Palestinian flags.
More than 4,700 Palestinians are currently detained in Israeli prisons, including 320 held under administrative detention orders, or imprisonment without charge, according to the Palestinian prisoner affairs ministry.