Smoke and flames are seen following what witnesses said was an Israeli air strike in Gaza City, July 16, 2014. [Photo/Agencies]

GAZA - The Islamic Hamas movement and Palestinian militant groups agreed late on Wednesday to a UN appeal of a five-hour humanitarian ceasefire with Israel on Thursday, a Hamas official told Xinhua.

Hamas and other Palestinian factions agreed to halt rocket firing into Israel for five hours on Thursday in response to a proposal by the United Nations, the official said on condition of anonymity, adding that the movement "will respond to any Israeli attacks on Gaza during the pause."

Earlier on Wednesday night, Israel Defense Forces (IDF) said it will enable a humanitarian window in Gaza between 10:00 to 15:00 local time (0700 to 1200 GMT) on Thursday, as a result of a dialogue with the United Nations. But it also added that if Hamas fires rockets at Israel during the humanitarian window, the IDF will respond with force.

It's the first pause of fighting since Israel and Hamas fighters have engaged in fierce cross-border attacks since last Tuesday when Israel started an all-out operation to halt Gaza rocket fire. The operation has claimed 223 Palestinian lives so far.

Before the agreement on the five-hour ceasefire, Hamas officially rejected an Egyptian initiative of ceasefire between Gaza militants and Israel earlier on Wednesday. In response, Israeli Prime Minister Benjamin Netanyahu said that "Israel would expand and increase" its campaign against Hamas and other militant organizations in the Gaza Strip until the rocket fire from Gaza comes to an end.