Gaza's Islamic Jihad announced Thursday that an Egyptian-brokered truce had been restored following a brief but intense confrontation a day earlier when Israeli warplanes pounded the Strip after heavy cross-border rocket fire.

But the truce, which was to have taken effect at 1200 GMT, was being tested after the Israeli military reported further rocket fire from Gaza hours later and launched retaliatory air strikes for a second night.

"Israel Air Force aircraft targeted four terror sites in the southern Gaza Strip and three additional terror sites in the northern Gaza Strip," a military statement released around midnight (2200 GMT) said.

Palestinian security officials and eyewitnesses said that the targets were facilities of the Hamas military wing, the Ezzedine al-Qassam brigades, near Gaza City and a base of the smaller militant Popular Resistance Committees in the southern town of Rafah.

The army said that five rockets hit Israeli soil during the evening and another two were intercepted midair by the Iron Dome missile defence system.

Three rockets had also struck during the morning, he said.

On Wednesday at least 60 rockets hit Israel.

No one has yet claimed responsibility for the Thursday rocket fire, but Gaza security sources linked what appeared to be a failed rocket attempt Thursday night to a Salafist splinter group.

They said the group may have been behind the explosion of a locally made projectile in the northern town of Beit Hanoun that injured five members of the same family, including a woman and two children.

Over the course of 24 hours, Israeli warplanes struck Gaza after militants fired scores of rockets over the border in the worst confrontation since an eight-day conflict in November 2012 between Israel and the Islamist movement Hamas which rules Gaza.

Although there were no casualties on either side, the violence was denounced by both Palestinian president Mahmud Abbas and British Prime Minister David Cameron at a news conference in the West Bank town of Bethlehem.

EU foreign policy chief Catherine Ashton added her voice.

"I strongly condemn the recent rocket attacks on Israel, for which the Palestinian Islamic Jihad, which is listed by the EU as a terrorist organisation, has claimed responsibility," she said in a statement

"There can be absolutely no justification for the deliberate targeting of innocent civilians, and I call for an immediate end to such acts."

Behind the scenes, Egypt worked to secure the renewal of a truce agreement to scale back the hostilities, officials in Gaza said.

"An Egyptian-brokered truce went into effect at 2:00 pm (1200 GMT)," Islamic Jihad spokesman Daud Shihab told AFP.

Earlier, Khaled al-Batsh, an Islamic Jihad leader, said Egyptian officials had contacted Hamas to "restore the truce" with Israel in force since November 2012.

But an Israeli defence official said he was "not familiar" with any ceasefire arrangement.

Despite the tit-for-tat violence, experts said Israel was not interested in a major confrontation in Gaza.

The confrontation began Tuesday when Islamic Jihad militants fired a mortar at Israeli troops allegedly trying to enter southern Gaza, prompting a retaliatory air strike that killed three of them.

On Wednesday, Islamic Jihad's armed wing, the Al-Quds Brigades launched a coordinated barrage of rockets at southern Israel that continued into the night, with the group putting the number at 130.

Israel responded by hitting 29 targets across Gaza overnight, including Islamic Jihad and Hamas bases. Another seven air strikes on southern Gaza followed during the morning.

Defence Minister Moshe Yaalon blamed both Islamic Jihad and Hamas, saying the latter was responsible for any fire emanating from its territory.

"Hamas is responsible for the Strip and if it does not know how to prevent fire on Israel from its territory, we will act against it and all of its broader interests," Yaalon said.

- Abbas condemns rocket fire -

Abbas, after initially being criticised for blaming the escalation solely on Israel, said Thursday that "we condemn all military escalation including rockets".

In remarks late on Wednesday, he had demanded that Israel "put an end to its military escalation in the besieged Gaza Strip," his spokesman said, drawing a sharp rebuke from Prime Minister Benjamin Netanyahu.

"How is it possible that he doesn't condemn the firing of rockets at innocent civilians," Netanyahu asked.

As both sides watched the border, experts said developments would depend on Hamas.

"Israel has no intention of entering a major operation now," said Yaakov Amidror, who served as national security adviser until November.

"But if there's a continued response from the other side, the IDF (army) will have to reconsider," he told army radio.