Israel announced Wednesday that it would halt all military operations against targets in the Gaza Strip for a period of five hours in order to allow humanitarian agencies to transfer food and medical supplies into the Hamas-controlled coastal enclave.

The ceasefire, which was unilaterally agreed upon by Israel, will take place from 10 a.m. to 3 p.m., the IDF said in a statement.

“This humanitarian window is meant to allow the civilian population of the Gaza Strip to engage in resupply for their humanitarian needs,” the statement said. “Should the humanitarian window be exploited by Hamas or other terror organizations for the purpose of launching attacks against Israeli civilian or military targets the IDF will respond firmly and decisively.”

UN Special Coordinator for the Middle East Peace Process Robert Serry had requested that Israel initiate the truce in the hopes that Hamas would join in later.

It was unclear which of the border crossings into the Strip would be opened for humanitarian purposes.

Meanwhile Wednesday, an Israeli delegation set out to Egypt in an attempt to formulate an official ceasefire agreement. Palestinian Authority and Hamas representatives are also in Cairo. The Israeli delegation includes Shin Bet chief Yoram Cohen, Prime Minister Benjamin Netanyahu’s associate Yitzhak Molcho, and security official Amos Gilad, Channel 10 reported.

Palestinian Authority President Mahmoud Abbas is set to meet in Cairo on Thursday with Egyptian President Abdel-Fattah el-Sissi, and will present a ceasefire proposal that includes the opening of the Rafah border crossing under the supervision of PA security forces, and the deployment of PA forces along the Philadelphi Corridor between Gaza and the Sinai peninsula, Palestinian sources told The Times of Israel on Wednesday.

Abbas is also to meet Thursday in Egypt with the deputy head of the Hamas political bureau, Moussa Abu Marzook, and discuss ceasefire terms with him. He may also meet with Hamas’s political bureau chief Khaled Mashaal in Turkey.

Egyptian security forces stand guard as an ambulance, carrying a Palestinian who was wounded in an Israeli air strike, crosses the Rafah crossing between Egypt and the southern Gaza Strip on July 12, 2014. (photo credit: AFP/SAID KHATIB)

Egyptian security forces stand guard as an ambulance, carrying a Palestinian who was wounded in an Israeli air strike, crosses the Rafah crossing between Egypt and the southern Gaza Strip on July 12, 2014. (photo credit: AFP/SAID KHATIB)

Israel does not oppose the idea of PA forces at Rafah, Israeli sources said. The proposal would mark a significant return of  Abbas’s forces to positions of authority in Gaza, seven years after Hamas seized the Strip from Abbas in a coup.

Also Wednesday, Hamas officially informed Egypt that it rejected its ceasefire initiative, a Hamas spokesman said. Speaking to the press in Gaza, Sami Abu Zuhri said the Egyptian initiative presented on Monday satisfied none of the Palestinian demands, and would have returned the situation on the ground to “the starting point.”

Abu Zuhri did not spell out Hamas’s conditions for a ceasefire, but the movement’s armed wing, the Izz ad-Din Al-Qassam Brigades, has previously indicated that those would include an immediate halt of Israeli operations, the opening of the Rafah border crossing with Egypt, the payment of salaries to thousands of Hamas civil servants, and an easing of the Israeli blockade on Gaza.

Hamas’s outright rejection of the Egyptian proposal dispelled earlier reports whereby Hamas had agreed to a 10-year ceasefire in return for Israeli concessions.

“Netanyahu’s threats and those of the occupation don’t scare Hamas,” Abu Zuhri said, adding that “the occupation will pay the price for the pure blood that it has spilled.”

He also lambasted Arab leaders for forsaking the people of Gaza.

“There is no official Arab activity to rescue Gaza,” he was reported by Hamas website Al-Resalah as saying. “We feel greatly betrayed by official Arab regimes; we have encountered no real official Arab position.”

Senior Hamas official Ghazi Hamad told AFP in Gaza City that the Egyptian plan was rejected “in its current form” and that Hamas had notified Egypt of the changes it was seeking.

“The initiative should include clear wording on fully lifting the blockade on Gaza, including opening all the crossings and releasing the rearrested prisoners from the [Gilad] Shalit deal in the West Bank,” Hamad said.

He was referring to a 2011 deal under which Shalit, an Israeli soldier seized in Israel and held hostage by Gaza terrorists for more than five years, was freed in exchange for 1,027 Palestinian security prisoners.

Another Palestinian official said that Hamas and other factions were objecting to the term “hostilities” in the Egyptian initiative, complaining that “what they are doing is self-defence and resisting the occupation, but what the occupation is doing is aggression”.

He said he hoped there would be “meetings between Egypt and the factions as soon as possible to adjust the wording of the initiative and get to a ceasefire.”

Avi Issacharoff, Elhanan Miller and AFP contributed to this report.