Palestinians hoping for the release of relatives under the latest exchange of the Gaza ceasefire waited uncertainly into the night on Saturday after Israeli Prime Minister Benjamin Netanyahu ordered a delay.
In the southern Gaza city of Khan Yunis as in the occupied West Bank city of Ramallah, families sought shelter from the bitter cold after waiting in vain for hours for the prisoners to arrive.
Um Diya al-Agha, whose son has spent 33 years in prison, said she had come to each of the six previous prisoner releases in the hope of finding him.
"Yesterday, I received news that he would be released, but I still can't believe that my son will be free after 33 years", she told AFP in the European Hospital in Khan Yunis, where freed prisoners had been expected to have a medical checkup.
"If my heart were made of iron, it would have melted and shattered. Every day, I have been waiting for this moment", the 80-year-old Khan Yunis resident said.
Six Israeli hostages held by Palestinian militants in Gaza were released earlier on Saturday. Israel was supposed to release 620 prisoners in exchange.
The great majority were captured in Gaza during more than 15 months of fighting. Eleven were detained before the war.
Um Hassan al-Qatta travelled from Gaza City hoping that newly released prisoners might have word on her teenage son, who went missing 314 days ago during the war.
"I don't know if he is alive or dead," she said. "I am happy for the hundreds of prisoners who have been freed, and I hope my son Hassan... will be released too."
Israeli sources said the prisoners' release had been delayed pending a decision by the prime minister.
Netanyahu "will hold a security consultation this evening", an Israeli official said on condition of anonymity.
A second source said that "once the security consultation concludes, a decision will be made regarding the next steps".
In Ramallah, prisoners' families holed up inside a cultural centre to escape the cold during their long wait. Many had made time-consuming journeys across the West Bank through multiple Israeli checkpoints.