Nine rockets were launched from the Gaza Strip at Israel on Thursday despite an announcement of a cease-fire by the Palestinian militant group Islamic Jihad.

Seven of the rockets hit open terrain in southern Israel and the other two were shot down by Iron Dome missile defense batteries, raising Thursday's missile count to 17, in the most intense hostilities between Israel and the Hamas-controlled enclave since 2012.

Shortly after midnight on Thursday, IDF forces struck within the Gaza Strip. According to the IDF Spokesman, Israel Air Force jets struck three targets in the Strip's north and four in its south.

An Islamic Jihad leader said on Thursday that Egypt had brokered a cease-fire agreement between his organization and Israel. "Following intensive Egyptian contacts and efforts, the agreement for calm has been restored in accordance with understandings reached in 2012 in Cairo," Khaled al-Batsh wrote on Facebook, referring to a truce that ended an eight-day Gaza war two years ago.

Batsh said Islamic Jihad, a militant group that began launching rockets into Israel on Wednesday after Israeli soldiers killed three of its fighters a day earlier, would hold its fire as long as Israel did the same.

But the Israeli army denied any cease-fire was reached with Gaza's militants.

IDF Chief of Staff Benny Ganz returned on Thursday from the United States, where he had spent several days for the IDF's fundraising gala. Upon his arrival in Israel, Gantz held several meetings with his staff to discuss the recent events, and also met with the heads of the Regional Councils bordering the Strip.

A senior security official in Egypt, which has brokered similar truces in the past, said Egyptian intelligence officials had been in touch with the sides and brokered an agreement. The official spoke on condition of anonymity because he was not authorized to speak to journalists.

A senior Defense Ministry official said earlier in the day he expected the fighting to die down soon.

At a meeting Thursday with the visiting British Prime Minister David Cameron, Israeli Prime Minister Benjamin Netanyahu vowed to step up the pressure on the militants. He was to meet with his Security Cabinet to discuss a further response, though expectations were that tensions would ease.

"Our policy in the south is clear. We harm those who try to harm us and respond fiercely to any attack," Netanyahu said. "The terrorist groups in Gaza need to understand that they are dealing with a very determined government and a very strong army."

Cameron has condemned the rocket fire.

Israeli Air Force jets attacked seven sites in the Gaza Strip on Thursday afternoon in response to a rocket barrage fired by Gaza toward the Israeli coastal cities Ashkelon and Ashdod.

The sites attacked were a tunnel, Gaza infrastructure and a command center, a source in the IDF told Haaretz. Palestinian sources reported that three Palestinians were wounded in Rafah as a result of the attack.

A senior Israeli officer told Haaretz Thursday that the IDF summoned "a limited number" of air defense reservists in response to the recent escalation. The soldiers summoned are from the IDF.

Palestinian militants in the Gaza Strip fired Grad rockets at Israel on Thursday morning striking open areas between Ashkelon and Ashdod, following a relatively quiet night.

The barrage was the latest renewal of tensions between Israel and Gaza, which escalated a day earlier when Islamic Jihad militants fired some 70 rockets at southern Israel over the course of the day. Ashdod ordered all schools lacking protected space to evacuate students.

The military wing of the Palestinian Popular Resistance Committees claimed responsibilities for the rocket fire, declaring in a statement that all of the group's units were on high alert along the border and would respond forcefully to any Israeli action in Gaza.

Israel Air Force carried out strikes in the Gaza Strip Wednesday evening, in response to the rockets. Jets struck 29 targets across the Strip, the IDF said in a statement.

"The IDF will not tolerate attempts to harm Israeli citizens and soldiers, and will continue to act forcefully and decisively against any who uses terror against the State of Israel. Responsibility [for the strike] lies with the terrorist organization Hamas."

Of the 70 missiles that were fired at Israel earlier, forty-one struck within Israeli territory, hitting various locations near the Strip. A 57-year-old woman was lightly hurt when she ran toward a safe zone. One missile hit Sderot, another landed within Shaar Hanegev Regional Council, and others struck areas around Netivot, Sdot Negev and Eshkol Regional Councils.

The flare-up is casting a shade on the weekend's Purim celebrations in Israeli communities in the vicinity of the Gaza Strip. "Everything is different because of the rockets," Shir Messika, a youth organizer in Hof Ashkelon Regional Council, told Haaretz. "As of now, the Purim party will be held as planned, but we're aware of the possibility the situation will escalate and we'll have to cancel Purim."

Similar concerns were voiced in the Merhavim Regional Council as well. "We continue with the preparations for the Purim parties set for the weekend and for next week, but we know there's a chance they'll be postponed," said Gal Sadeh, an employee of the regional council.

Open gallery view Israeli explosives experts stand by a rocket fired from the Gaza Strip that struck near the coastal city of Ashkelon, Tuesday, Feb. 26, 2013. Credit: AP