As Israeli jets hammer the Gaza Strip amid a barrage of Palestinian rockets on cities in the Negev desert, pressure has been mounting for a new invasion of the Hamas-ruled territory, a move that could draw global condemnation and threaten relations with Egypt.

Clashes between the Israelis and extremist Palestinian groups the Popular Resistance committees and Islamic Jihad in Gaza escalated in recent days.

Palestinians have fired scores of rockets into Israel from the Gaza Strip but the attacks have caused little substantial damage.

Israeli leaders have been saying for months the military will have to invade Gaza at some point because the Jewish state cannot accept having Hamas and Iranian missile bases there.

Despite the fierce global censure of Israel's 22-day invasion of Gaza Dec. 27, 2008, in which some 1,400 Palestinians, mainly civilians, were killed, Israeli military Chief of Staff Lt. Gen. Benny Gantz declared on the third anniversary of Operation Cast Lead that another large-scale attack on the Gaza Strip was looming.

"I believe the state of Israel cannot continue to live under the active threat of Hamas in the Gaza Strip," he said. "Sooner or later, there will be no escape from conducting a significant operation."

On Jan. 3, in a high-profile ceremony seen as a gesture of defiance toward the United Nations, which condemned Operation Cast Lead amid allegations of Israeli war crimes, Gantz promoted one of its commanders to brigadier general.

Col. Ilan Malka, who led the Givati Brigade during that offensive, had been accused of bombing civilians but was cleared by Israel's military advocate general in December 2011.

On Jan. 17, The Jerusalem Post reported the general staff ordered the Southern Command, which covers the Gaza front, to prepare for a possible large-scale incursion into the 146-square-mile coastal strip where 1.7 million Palestinians live.

As clashes continued Monday, Egypt was apparently making a major effort to end the fighting, apparently aiming to head off an escalation that could drag Egyptian forces in the Sinai into the fighting.

A high-level Hamas delegation headed by Moussa Abu Marzouk, one of the movement's top political chiefs, arrived in Cairo Sunday. Another Hamas team reached Cairo a day earlier.

Hamas, which hasn't been involved in the clashes, made it clear it sought to maintain the relative calm that had prevailed with Israel until Friday but it made no apparent move to stop the attacks blamed on Islamic Jihad and the PRC.

The Israelis warned they will escalate their actions if the rocket barrage continues and didn't appear to be overly concerned about international criticism.

Officials said the world was probably indifferent because the Israeli action hasn't inflicted extensive civilian casualties. The bloodletting in Syria was also probably diverting global attention.

Israeli leaders say they don't want to escalate the clashes. But it was their decision to launch the airstrike that killed PRC leader Zihair al-Qaisi Friday, claiming he was planning a major terrorist attack on Israel through Sinai, that triggered the sharp intensification in the Palestinian rocketing.

Qaisi's three predecessors were all assassinated by the Israelis.

In comparison, Israel had responded to desultory rocket fire in February by bombing smuggling tunnels used by Hamas, considered minor operations.

Some Israeli commentators indicated that with the world distracted they believe the military, along with hawkish Prime Minister Binyamin Netanyahu and Defense Minister Ehud Barak, now seek an escalation.

They argue that Netanyahu doesn't want peace negotiations with Hamas and the Fatah-controlled Palestinian Authority in the West Bank, and the attendant pressure on Israel to relinquish the West Bank.

Hamas' recent moves toward a more pragmatic position, eschewing violence, and its steps to reconcile with Fatah after a lengthy split undermines Netanyahu's repeated claim that Israel "has no peace partner."

"Thus," veteran Israeli commentator Zvi Barel observed in the liberal Haaretz daily Sunday, "Hamas must be dragged toward military activity against Israel.

"And nothing is easier, at least in Israel's estimation, than to launch a 'unilateral' attack against a wanted non-Hamas man, to wait for the response to come, and hope that Hamas joins in.

"So far, it hasn't happened … Hamas still prefers the diplomatic channel … Israel apparently needs to wait for another opportunity."