JERUSALEM, March 13 (Xinhua) -- A senior Israeli military official on Tuesday said that last week's targeted assassination of an Islamic militant headed off a cross-border attack with " strategic implications" for already-tense relations with Cairo.

"Always -- in our constellation -- the peace between us and Egypt is very important, and the national security of Egypt is very important as well," Maj.-Gen. (res) Amos Gilad, the Defense Ministry's Director of Policy and Political-Military Affairs, told reporters in a conference call focusing on the targeted assassination.

"But, having said that, the most important detail is to protect the lives of Israelis," Gilad said, adding that, "this is the responsibility of the government."

A pinpoint Air Force strike on Friday killed Popular Resistance Committees (PRC) operative Zuhair al-Kaisi in his vehicle as he headed towards carrying out a major terror attack against Israel along the Egyptian border, according to the Israel Defense Forces (IDF) spokesman.

Soon thereafter, PRC and Islamic Jihad militants began pouring rocket and mortar fire into Israeli cities and towns, in amounts that -- at one point -- exceeded those during Operation Cast Lead in late 2008 and early 2009.

Rocket crews fired some 220 projectiles at Beersheva, Ashdod, Ashkelon and elsewhere, but three Iron Dome anti-missile system batteries successfully downed about a quarter of those aimed at population centers, while allowing others to harmlessly fall in open areas. Some one million Israelis were forced into bomb shelters for the interim.

Several dozen people were wounded or treated for shock after each Grad and Kassam rocket barrage, but there were no fatalities.

However, the army said the air force retaliatory strikes on Palestinian rocket squads killed 26 people -- 22 of them militants.

An Egyptian-brokered deal reached overnight Monday brought about a sharp lessening of hostilities between Israel and the militants, an agreement which Gilad praised.

"Egypt is very important ... they have succeeded here; they deserve credit," Gilad said, adding that "only Egypt" can foil similar cross-border attacks from the Sinai no-mans land.

Palestinians fired six mortars into Israel on Tuesday, the army said, but there were no reports of injury or damage.

Last August, Al-Kaisi was responsible for a similar attack out of the Sinai against motorists traveling along an isolated highway near the border, which killed eight Israelis and wounded several dozen others.

In that attack, Israeli forces in hot pursuit chased the fleeing perpetrators back into Egyptian territory, but mistakenly killed a number of Egyptian security personnel in a firefight. The event brought bilateral relations to their lowest point in decades.

"The decision to eliminate Kaisi was correct," Defense Minister Ehud Barak said during a visit to the army's Gaza Division, adding that "right now the results are good, and we are preparing for the next time we'll need to take action."

IDF Chief of Staff Lt.-Gen. Benny Gantz said during a visit to an induction center on Tuesday that, "We are following events in Gaza, and if the terror organizations will really stop shooting, the IDF will respond accordingly. Quiet will be answered with quiet, but if it gets noisy in the southern settlements, it will be noisy in Gaza as well."