Shops were shuttered in the Palestinian commercial capital on Sunday in solidarity with nearly 300 Palestinian prisoners on hunger strike against Israeli detention without trial.
Black-and-white flags bearing slogans such as "Freedom for Prisoners" and "Chains must be broken" flew in the streets of the West Bank city of Ramallah, where the commercial strike was observed.
In Hebron, also in the Israeli-occupied West Bank, dozens of Palestinian protesters marched in the streets in support of the hunger strikers.
The hunger strike was begun on April 24 by a group of 120 Palestinian prisoners held under what Israel terms administrative detention. They were later joined by 170 other inmates who also demanded that Israel abolish the procedure, which has drawn international criticism.
Israel's Prisons Service said 65 hunger strikers were being treated in hospitals, although none was in critical condition and all were conscious. The Palestinians put the number of prisoners who had required hospital care at 100.
"The weight of striking prisoners has gone down by an average of 16 kilograms," said Jawad Bolus, a Palestinian lawyer who visited eight of the hospitalized inmates.
On Friday, a UN spokesman said Secretary-General Ban Ki-moon was concerned about "reports regarding the deteriorating health of Palestinian administrative detainees". Ban, the spokesman said, reiterated his long-standing position that they be charged or released without delay.
Israel says detention without trial of Palestinians suspected of security offences is sometimes necessary to avoid court proceedings that could expose sensitive intelligence information or informants.
Lawyers who visited prisoners over the past several weeks said Israel had begun a dialogue with some of the hunger strikers' representatives but no progress had been made.
Palestinians regard those jailed by Israel as heroes in a struggle for statehood. Israel says Palestinians involved in violent anti-Israeli activities are terrorists.