Prime Minister Benjamin Netanyahu and Defense Minister Moshe Ya’alon ordered the IDF Friday to “respond with force” to rocket fire against Israel originating from the Gaza Strip, after Palestinian terror groups in Gaza broke the ceasefire at 8 a.m. and began firing dozens of rockets at southern Israel.

Hamas officials refused to extend the three-day cease-fire, but said they were willing to continue negotiations in Cairo. Israel said it would not negotiate under fire and would protect its citizens by all means. The Israeli delegation left Cairo on Friday morning, and it was not clear if it would return. Egyptian officials were continuing talks with the Palestinian delegation, which was reportedly divided, with PA representatives having urged an extension of the ceasefire, overruled by Hamas representatives.

Within minutes after the temporary truce expired at 8 a.m., Gaza militants began firing rockets. By afternoon, some 40 rockets had been fired. Some 30 landed in Israel, several were intercepted and at least four fell short in Gaza, the army said. Four Israelis were hurt, one seriously. One rocket landed meters from a gasoline station. Later, a rocket directly hit a home in Sderot.

Israel eventually responded with what the military said were strikes “across Gaza.” Police in Gaza said that most of the strikes hit empty fields, but that one struck the backyard of the Nour al-Mohammadi Mosque in the Gaza City neighborhood of Sheik Radwan, killing a 10-year-old boy.

Still from Al-Jazeera's footage, broadcast on Wednesday, August 6, showing Hamas gunmen, weapons and tunnels in place ahead of Hamas's breach of the truce on August 8 (MEMRI screenshot)

Still from Al-Jazeera’s footage, broadcast on Wednesday, August 6, showing Hamas gunmen, weapons and tunnels in place ahead of Hamas’s breach of the truce on August 8 (MEMRI screenshot)

Police also reported fire from Israeli tanks on northern Gaza and from Israeli gunboats at the central area of the strip.

In Israel, the army said it was prohibiting gatherings of more than 1,000 people in Jerusalem, Tel Aviv and other areas within 80 kilometers (50 miles) of the Gaza border because of the rocket fire.

The resumption of violence cast doubt over the Cairo negotiations.

Both Israel and Hamas are under international pressure to reach a deal. As part of such an arrangement, Israel wants to see Hamas disarmed or prevented from re-arming, while Hamas demands Gaza’s borders be opened. Israel and Egypt maintain a security blockade of Gaza to prevent Hamas importing more weaponry.

Prime Minister Benjamin Netanyahu speaks at a press conference at his Jerusalem office, on August 6, 2014. (Photo credit: AFP/Jim Hollander/Pool)

Prime Minister Benjamin Netanyahu speaks at a press conference at his Jerusalem office, on August 6, 2014. (photo credit: AFP/Jim Hollander/Pool)

Hamas, which has seen its popularity boosted for confronting Israel, entered the Cairo talks from a point of military weakness after losing hundreds of fighters, two-thirds of its rockets arsenal and all of its attack tunnels.

With no definitive statement that it would return to open war, the group appeared to be keeping its options open while several smaller Gaza militant organizations claimed responsibility for Friday’s rocket fire.

Israeli government spokesman Mark Regev blamed Gaza militants for breaking the ceasefire. “The ceasefire is over,” Regev said. “They did that.”

The three-day truce came after a month of Israel-Hamas fighting, the third cross-border confrontation in just over five years.

Israel launched an air campaign on the coastal territory on July 8, and nine days later, sent in ground troops to target rocket launchers and cross-border tunnels built by Hamas for attacks inside Israel.

Since then, Israeli strikes on Gaza killed nearly 1,900 Palestinians, and displaced tens of thousands of people. Israel says 750-1,000 of the dead are gunmen, and blames Hamas for all the civilian fatalities, since Hamas used Gazans as “human shields” for its rockets and tunnels, Netanyahu said Wednesday.

Sixty-seven people, all but three of them soldiers, were killed on the Israeli side, and Gaza militants fired more than 3,000 rockets at Israel over the past month. Eleven soldiers were killed by gunmen emerging inside Israel from the cross-border tunnels, which Netanyahu said were built as Hamas planned to carry out “catastrophic” acts of terrorism against Israelis.

Israel and Egypt imposed the blockade after the violent Hamas takeover of Gaza in 2007. The closure led to widespread hardship in the Mediterranean seaside territory, home to 1.8 million people. Movement in and out of Gaza is limited, the economy has ground to a standstill and unemployment is over 50 percent.

Israel argues that it needs to keep Gaza’s borders under a blockade as long as Hamas, designated a terrorist group by Israel, the US and others, tries to smuggle weapons into Gaza or manufactures them there. Hamas refuses Israel’s demands, backed by the US, EU and others, that it disarm.

It has said it is willing to hand over some power in Gaza to enable its long-time rival, Western-backed Palestinian Authority President Mahmoud Abbas, to lead Gaza reconstruction efforts but that it would not give up its arsenal and control over thousands of armed men.

The Gaza war grew out of the abduction and killing of three Israeli teens in the West Bank in June. Israel blamed the killings on Hamas and launched a massive arrest campaign, rounding up hundreds of the group’s members in the West Bank, as Hamas and other militants unleashed rocket fire from Gaza. Israel says the West Bank organizers of the terror cell, who is under arrest, has admitted the June killings were ordered and funded by Hamas in Gaza.

Hamas refused to extend the ceasefire and vowed to renew rocket attacks after Israel rejected all of the group’s core demands in indirect talks in Cairo, senior Hamas officials stated Friday. Hamas had demanded that Israel agree, in principle, to end Gaza’s border closure, release Hamas operatives arrested in recent weeks in the West Bank, and other measures.

“We have one position, we refuse to extend the ceasefire, it is a final decision,” said one Hamas official after a long meeting with Egyptian mediators, AFP reported.

“Israel did not propose anything,” he added. “It did not agree to end the blockade [of the Gaza Strip].”

Palestinian Hamas supporters gather for a rally in Gaza City, Gaza Strip, Thursday, Aug. 7, 2014 (photo credit: AP/Lefteris Pitarakis)

Palestinian Hamas supporters gather for a rally in Gaza City, Gaza Strip, Thursday, Aug. 7, 2014 (photo credit: AP/Lefteris Pitarakis)

On Wednesday, IDF Chief of Staff Lt. Gen. Benny Gantz said Israel was prepared to strike Hamas leaders when they emerge from hiding, and warned that the army would retaliate strongly if the terror organization resumed firing rockets at Israel.

“Its commanders sit in their bunkers in hiding, and everywhere we can hit them, we will hit, if we want to. They will go outside when they please — if they do, they will see the extent of the damage to their fighters and the damage in the Gaza Strip, which unfortunately, is Hamas’s fault. I hope this lesson will be internalized in the Gaza Strip, because we will not hesitate to continue to mobilize our forces as necessary to ensure the security of Israeli citizens,” he said.

IDF Chief of Staff Benny Gantz gives a statement to the media near the Israel-Gaza border on July 20, 2014 (Photo credit: Mendy Hechtman/Flash90)

IDF Chief of Staff Benny Gantz gives a statement to the media near the Israel-Gaza border on July 20, 2014. (photo credit: Mendy Hechtman/Flash90)

“We aren’t done,” Gantz added. “If there are incidents, we will respond to them.”

Despite the withdrawal of all its troops from Gaza by the time the three-day truce began early on Tuesday, Israel has retained tens of thousands of troops along the border who are ready to respond to any resumption of fighting.

AFP contributed to this report