Addressing an increase of rocket fire into Israel from Gaza, Defense Minister Ehud Barak on Monday advised Gaza's Hamas rulers to "watch their step, and not to cry crocodile tears if they force [Israel] to take action."

Army Radio on Monday quoted Israeli security experts as saying that Hamas has lessened its determination to prevent the rocket fire from Gaza, due to growing dissent in the coastal strip.

Speaking at an event marking the successful completion of testing for the Iron Dome short-range missile defense system, Barak said that Israel's three-week incursion into Gaza last winter had made Hamas reluctant to resume the rocket fire that triggered the offensive.

"The deterrence achieved during Operation Cast Lead still exists, and it is strong. The fire in recent days stems from Hamas' inability to rein in Jihad bodies and independent groups."

Barak also said he believed Hamas was unable to rein in the other militant groups.

"I think the recent days reflect the inability of Hamas to control the dissident groups, the Popular Committees or Islamic Jihad, who are trying to break the tranquility," Barak told Reuters during the unveiling of the anti-rocket system.

"Hamas is well deterred from trying another direct collision with Israel. I hope that they will take over - or else," the defense minister said when asked if a new Gaza conflict was possible.

Asked about Barak's comments, Hamas official Sami Abu Zuhri said the Palestinian attacks were carried out in response to "continued Israeli aggression".

A Palestinian official, who asked not to be identified, said Hamas planned to meet other groups soon to urge restraint, unless Israel stepped up its attacks.

On Sunday, an Israel Air Force strike in central Gaza killed three Palestinian militants, including a senior field commander, hours after Prime Minister Benjamin Netanyahu vowed a "powerful response" to recent rocket and mortar shell attacks from the coastal territory. The IAF strike targeted a cell as its members were launching rockets at Israel.

Barak said Monday that he supported Netanyahu's plan to close off Israel's southern border with Egypt by building a NIS 1.5 billion fence which the prime minister said would prevent the entry of "infiltrators and terrorists."

"Good fences make good neighbors," he said.

The defense minister also said "Iron Dome" would "change the equation" and could deter militants from launching attacks.

"It is a major change and provides the Israeli civilian population, once deployed in the coming years, cover against small sized rockets and missilettes," he said.

Israel's three-week offensive in the Gaza Strip last winter was followed by relative calm, with rocket attacks from the coastal enclave a rare occurrence. However, over the last week, in a dramatic escalation, Gaza militants fired over 20 rockets and mortar shells into Israel, prompting swift retaliation.

On Sunday, an Israel Air Force strike in the central Gaza Strip killed three Palestinian militants, including a senior field commander, hours after Netanyahu vowed a "powerful response" to any attacks from the coastal territory.

The security officials told Army Radio that Israel's plan to build the security fence along its southern border with Egypt and the delays in the Israel-Hamas prisoner exchange deal, have swayed Gaza public opinion against the ruling party.

Meanwhile, in contrast to previous Israeli attacks on Gaza, Sunday's operation drew no condemnations from any Palestinian group, and no threats of retaliation.

Arab media covered the incident in brief, without the customary footage of wounded Palestinians, bodies and blackened vehicles, Army Radio reported.

The absence of threats and condemnations left room for Hamas rivals on the airwaves. PLO Executive Committee Secretary General Yasser Abed Rabbo said "Hamas, or its allies, are operating under this excuse or that one, in advancement of their own interests they are leading the Palestinian people to slaughter."

The low profile of this event could be attributed to recent efforts to reconcile between the rival Palestinian parties Fatah and Hamas. The Lebanese daily As-Safir reported Monday that a planned summit between the Saudi king and the Syrian president was planned for Thursday in Riyadh, focusing on mending the rift between Fatah and Hamas. Egyptian President Hosni Mubarak may also attend the summit.

If the summit goes as planned, it will be the first meeting between Syrian President Bashar Assad and Mubarak in over a year, and will also focus on rehabilitating broken ties between Egypt and Syria.