Gaza City (CNN) -- For residents of Gaza and southern Israel, the fleeting period of calm is over.

The Israeli military said it carried out strikes on militant targets in Gaza on Friday in response to a barrage of rocket fire after a three-day truce in the region came to an end without a longer-term agreement.

At least 50 rockets were fired at Israel after the cease-fire expired Friday morning, the Israel Defense Forces said. Most of the rockets hit unpopulated areas, but one injured a civilian and slightly injured a soldier, the IDF said.

Israeli Prime Minister Benjamin Netanyahu and Defense Minister Moshe Ya'alon ordered the military to respond forcefully to the resumption in rocket fire, Israeli officials said. The IDF said it "targeted terror sites across the Gaza Strip."

Several explosions were heard in Gaza City as Israeli fighter jets flew overhead. Local media reported airstrikes elsewhere in the territory. One strike in Gaza City killed a 10-year-old boy, said Ashraf el-Qedra, a spokesman for the Palestinian Ministry of Health.

Hamas, the Islamic militant group that holds power in Gaza, said that Palestinian officials at peace talks in Cairo hadn't agreed to extend the truce but would continue negotiations.

But Israeli government spokesman Mark Regev told CNN that the resumption of rocket fire means Hamas has "broken the fundamental premise of the talks in Cairo."

The Israeli delegation arrived back from Egypt about an hour before the cease-fire ended, Israeli officials said.

Israel says truce violated

Israel, which pulled its ground forces out of Gaza earlier this week, had said Thursday it was willing to extend the truce unconditionally.

Two militant factions -- Islamic Jihad and the Al-Nasser Salah al-Din Brigades -- who have fought alongside Hamas in Gaza under the banner of "the resistance" said they had fired rockets at Israel on Friday.

"The enemy ended the cease-fire when he refused to accept the demands of the resistance and he bears responsibility for the consequences of that," the military wing of Islamic Jihad said in a statement.

Roughly three hours before the truce was due to end, the IDF said two rockets fired from Gaza had hit southern Israel, without causing any casualties. "Terrorists have violated the cease-fire," the IDF wrote on Twitter.

It was unclear who in Gaza, where multiple militant factions are active, launched the two rockets, which landed near Eshkol in southern Israel.

Hamas denies responsibility for the rockets fired before the cease-fire ended, said Sami Abu Zuhri, a spokesman for the group. The allegations "are based on Israeli reports aimed at confusing the situation," the Gaza-based spokesman said.

No breakthrough in talks

The reports of rocket fire came as hopes faded for an agreement to extend the Egyptian-brokered cease-fire, which began Tuesday.

Under the truce, Israeli and Palestinian delegations held indirect talks in Cairo through Egyptian go-betweens. But the two sides appeared to be too far apart in their positions.

A Palestinian member of the negotiating delegation, not authorized to speak to the media directly about the talks, told CNN on condition of anonymity that the two sides failed to agree on the wording of a cease-fire extension that included the Palestinian demand for Israel to lift the blockade on Gaza. The official also indicated the Palestinian demands to open an airport and a seaport, and to release prisoners who had been released and rearrested in June, were declined by the Israeli negotiators.

Despite the lack of a breakthrough in the talks, Israel had said Thursday that it was willing to extend the cease-fire unconditionally. The country's military said earlier in the week that it had achieved its goal of destroying Hamas' network of tunnels that extend under the border into Israel. In light of the recent wave of rocket attacks, on Friday the country's Foreign Ministry said via Twitter that Israel "will not conduct negotiations while under fire."

But Hamas, one of several factions in the Palestinian delegation, meanwhile, says the longstanding Israeli blockade of Gaza must end before a lasting peace deal can be reached.

"Up until this minute, the Palestinian delegation did not receive the Israeli response on any of the Palestinian demands and positions in this conflict in order to reach a cease-fire fire agreement or in trying to end the war," said Izzat Risheq, a Hamas senior leader.

The Hamas leader said the Israelis are "evasive and dishonest and are just wasting time. They bear the full responsibility for the breakdown of the talks," adds Risheq.

As violence flared once again Friday, a senior PLO official said that cease-fire talks in Cairo were still possible and Israel should "lift the siege of Gaza immediately."

"Talks are not dead" Saeb Erakat, a veteran Palestinian negotiator told CNN.

While the spokesman for the Egyptian Foreign Ministry, Ambassador Badr Abdel Atti, told CNN that discussions are still "ongoing" but could not elaborate on the specifics in an effort not to "jeopardize the talks."

Civilian population suffering

The lack of a deal appears to be reviving a conflict that brought death and destruction to large areas of Gaza and thousands of rockets fired at Israel.

Renewed hostilities also deepen the misery for people in Gaza who were wounded, displaced or deprived of basic necessities by the first four weeks of fighting.

On Friday, the Palestinian Ministry of Health issued new casualty numbers for the conflict -- 1,893 deaths, including 446 children, and 9,805 injured.

It's unclear how many of the Palestinian dead were militants.

The United Nations has estimated that at least 70% of the dead were civilians. The Israel Defense Forces believes it killed about 900 militants -- roughly half of the dead.

Israeli officials have said 64 Israeli soldiers and three civilians in Israel died. Israel's Iron Dome missile defense system intercepted many of the rockets fired at populated areas of the country.

Additionally, about 65,000 Gaza residents lost their homes to the fighting, according to U.N. estimates. The territory is also short on running water, power and medical supplies.

"We have an emergency situation in Gaza," Erakat said.

(CNN) -- If the Gaza truce holds and Israel's Operation Protective Edge comes to its conclusion, some things are certain.

Both Israel and Hamas will declare military victory -- Israel pointing to the destruction of militants' tunnels and depletion of Hamas' rocket supply; Hamas pointing to dozens of dead Israeli troops and the survival of Hamas leadership in Gaza.

But unlike in previous conflicts, when Hamas had the support of many Arab nations, things have changed. This time, as CNN has reported, the fighting between Israel and Hamas has been a proxy war for the Mideast.

Key regional players Jordan, Egypt and Saudi Arabia have their own reasons to want to fend off the Muslim Brotherhood, of which Hamas is part, experts say. And Europe, like the United States, lists Hamas as a terrorist organization for its numerous attacks on civilians.

But the group does have the support of some countries.

"It's no longer the Muslims against the Jews," said Danielle Pletka, vice president of foreign and defense policy studies at the American Enterprise Institute. "Now it's the extremists -- the Muslim Brotherhood, Hamas, Hezbollah, and their backers Iran, Qatar and Turkey -- against Israel and the more moderate Muslims including Jordan, Egypt, and Saudi Arabia."

A look at some key Hamas supporters:

Turkey

Prime Minister Recep Tayyip Erdogan openly supports Hamas.

"Erdogan has tried to use the cause of the Brotherhood to bolster his own Islamist credentials at home," says Eric Trager, of the Washington Institute for Near East Policy.

Turkey also has "more of an ideological sympathy with the Brotherhood," Trager says.

Qatar

Qatar supported the Muslim Brotherhood in Egypt -- which was toppled from power in a coup last year. Qatar funds many Muslim Brotherhood figures in exile, including Hamas political leader Khaled Meshaal, who is believed to have orchestrated numerous terrorist attacks.

"Qatar has a long history of providing shelter to Islamist groups, amongst them the Muslim Brotherhood and the Taliban," Shashank Joshi of the Royal United Services Institute tells Time.

Advocating for Hamas is beneficial to Turkey and Qatar in their political objectives because the cause draws popular support at home, says world affairs writer Frida Ghitis in a CNN.com column.

But some question whether Qatar's support still is for Hamas is still strong. The country's financial support to the group "largely dried up" as Qatar sought "to mend ties with its neighbors, with whom it had fallen out in part for backing the Muslim Brotherhood in Egypt," the Council on Foreign Relations said.

While Qatar and Turkey are powerful allies, "Hamas might wish for more support given the breadth of the Arab world," Time reported.

Iran and Syria

In the past, Iran and Syria supported Hamas. Iran supplied the group with weapons; Syria was home to Meshaal.

But Meshaal did not support Syrian President Bashar al-Assad in the country's civil war. In 2012, Meshaal left for Qatar, causing a breakdown in his relationship with both Syria and its ally Iran, says Firas Abi Ali, head of Middle East and North Africa Country Risk and Forecasting at the global information company IHS.

And while Iran still professes to support Hamas, such claims "are more ostentatious, showy, exaggerated and theatrical rather than genuine and practical," writes Majid Rafizadeh, an Iranian-American scholar at Harvard University, in a column for al Arabiya.

Iran, which is a Muslim but not an Arab nation, "uses Hamas (as well as Tehran's support for the Palestinian cause) as a tool to project its power and influence in the Arab world," he argues.

The Council on Foreign Relations says Iran, while cutting its funding to Hamas in recent years, "sought to bolster its ties to other resistance groups in the region, such as Islamic Jihad."

Hezbollah

The Lebanese militant group based in Lebanon is aligned with al-Assad's regime in Syria. During the conflict, Hezbollah reached out to Hamas, praising its "steadfastness."

This does not mean the relationship is repaired to where it stood before Syria's civil war, but "a new realignment might happen," Farwaz Gerges of the London School of Economics told Time.

Popular support

Hamas' greatest support in the wake of the conflict with Israel may be from the public in Gaza and other parts of the Arab world.

"Hamas is not a monolith, nor is it only a terrorist group," Ed Husain of the Council on Foreign Relations writes on CNN.com. "It is a social movement, with a mass membership, a popular message of resistance that resonates across the Muslim world, and a political party with which we must negotiate."

Some analysts believe Hamas will emerge stronger from the fight with Israel. The conflict "will only further radicalize the Palestinian population -- and alienate frustrated friends in the United States," Mark Perry of Foreign Policy argues.

Before Operation Protective Edge, a poll by the Washington Institute for Near East Policy found that most Palestinians in Gaza oppose a two-state solution and want to work toward abolishing Israel -- a goal that is in line with Hamas' charter.

But the poll also found most Palestinians support nonviolent methods of achieving their goals.

Support could affect arms supply

While Hamas' recruitment might soar now, militarily the group "is on the ropes," with tunnels destroyed and much of its rocket supply depleted, writes Rick Francona, retired U.S. Air Force intelligence officer and CNN military analyst.

"After similar conflicts in the past, Hamas has been rearmed and resupplied by its supporters, primarily Iran and to some extent Syria. The most efficient method for the rearming and resupply effort has been via the large number of smuggling tunnels between Gaza and Egypt's Sinai Peninsula.

"That is not likely to be the case this time -- another blow to Hamas, which it must factor in to its assessment of this conflict as well as its future planning."