A single mortar shell fell in an unpopulated area in the Eshkol region Thursday morning. The mortar, fired by terrorists from the Gaza Strip, caused no damage or injuries, but broke the relative calm of the previous few hours.

The explosion was the first to be heard in the area following roughly 10 hours of calm, a day after Gaza-based terror groups fired more than 80 missiles at communities in the south of Israel, injuring five people and causing damage to eight houses.

The calm was a result of an Egyptian-mediated ceasefire that went into effect at midnight.

The truce, believed to have been negotiated by Egyptian intelligence officer Maj. Gen. Nader al-Aasr, stipulated that the IDF would halt its retaliatory strikes into the Gaza Strip if Hamas prevented rockets from being fired into Israel.

But Amos Gilad, a top aide to Defense Minister Ehud Barak, denied Thursday morning that Israel had reached an agreement with Hamas.

“There is no ceasefire agreement. There never was and never will be an agreement with Hamas. It is a murderous organization. The only thing that was settled was that there would be an effort to bring about calm,” Gilad said in an interview to Army Radio.

Egyptian security forces have “a very impressive ability” to convey to the militants that it is in their “supreme interest not to attack,” he said.

“We are in regular contact with the Egyptians, but they don’t need us to forge deals,” said Gilad. “Egypt sees terrorism as a serious threat. Al-Qaeda killed Egyptian soldiers. Terror is our common enemy.”

A Palestinian official told reporters Wednesday that Hamas had promised Cairo to calm the situation down and Israel said it would refrain from attacks unless it was subject to rocket fire.

However, on Thursday morning Hamas spokesman Fawzi Barhoun said that rocket fire at Israeli communities was a “natural response to the crimes of the occupation” and announced that armed forces in Gaza would react “with more strength” in the future.

A security official told Channel 10 news Wednesday evening that the IDF preferred quiet to a ramping-up of tensions.

“Military action would likely ignite the region, which is a matter that will require a prolonged military operation with casualties,” the official said.

Sources in the Israeli government reported that the Hamas leadership forwarded messages to Jerusalem through Egyptian intermediaries requesting a ceasefire, Israel Radio reported Wednesday night. The sources in Jerusalem believed that Hamas lacked the will to be dragged into a prolonged conflict with Israel, and that Israel inflicted serious damage to the group in airstrikes in the past day.

“An Egyptian-mediated truce is something that repeats itself because of their interest in regional tranquility,” the security source told Channel 10.

“Hamas and the [Islamist] factions [in the Gaza Strip] are interested in silence, according to our assessments, on account of Eid al-Adha in the coming days. A mutual interest has been created in which both we and they are interested in quiet,” the source said, referring to the major Muslim holiday.

Israeli leaders on Wednesday threatened an extensive military response if rocket fire continued. Defense Minister Ehud Barak said that a ground incursion was a possibility, though not a preferable one.

Israel’s UN ambassador, Ron Prosor, wrote to the UN Security Council warning members that if they don’t condemn the rocket attacks, “there could be tragic consequences” because Hamas and other militants will interpret the silence “as a green light for terror and provocation.”