The Israel Defence Forces went on high alert this week as Hamas threatened not to renew their ceasefire with Israel in the Gaza Strip.

The six-month truce between Israel and Hamas was due to expire today (Friday). While Israel prefers to extend it, Hamas appears to be split between continuing the pact and ending it. Damascus-based Hamas political leader Khaled Mashal said on Sunday that the ceasefire would not be renewed, while Hamas officials in Gaza said only that the issue was under review.

Defence Minister Ehud Barak, a proponent of extending the ceasefire, dispatched a top aide, Maj-Gen (res) Amos Gilad, to Cairo for talks with the Egyptians about the situation.

Israel, officials said, is unlikely to invade Gaza even if the ceasefire is not extended as long as none of the rockets inflict large numbers of casualties. On Wednesday three people were lightly injured after a Kassam struck Sderot, on a day in which over 20 missiles were fired into Israel from the Strip. Since November 15, some 100 missiles have hit Israel, while the IDF have attacked five rocket squads in Gaza.

“We are not deterred from an operation in Gaza but we are also not rushing into one,” Mr Barak said. “Calm will be met by calm but if there is no choice we will act when and where we see fit.”

Mr Barak added that a continuation of the ceasefire would also help secure the release of captured soldier Gilad Shalit. On Sunday, Hamas held a 200,000-strong rally in Gaza City marking the 21st anniversary of its founding. During the rally, a militant dressed in an IDF uniform took to the stage and impersonated Mr Shalit while begging in Hebrew to go home.

“Hamas will likely in the end decide to extend the ceasefire since it wants the crossings open into Israel and Egypt,” a senior IDF officer said. “Hamas is torn between Iran, which wants to end the ceasefire and Egypt, which is asking the terror group to extend it.”

Israeli Foreign Minister Tzipi Livni called on the government to respond militarily to each Kassam fired into Israel. “Every [rocket] fired from Gaza requires us to respond in order to protect civilians,” Ms Livni said.

Defence officials said that there was concern that Hamas would launch a series of attacks against Israel — possibly trying to kidnap soldiers — to enter the new ceasefire with an advantage.

“Hamas wants new rules for the truce,” said Mr Gilad. “Israel will not allow this to happen and will not give in to Hamas demands.”