Israeli Defense Minister Ehud Barak said Tuesday that his government is weighing a number of measures in order to restore deterrence against Gaza Strip militants that have bombarded southern Israeli cities for four straight days.

"The current round of violence is clearly not over and we will decide how and when to retaliate once the need arises," Barak said during a situation assessment with senior officers at the army's Gaza Division headquarters, according to a statement sent to Xinhua.

The defense minister would not elaborate on how a military escalation against Gaza could unfold, allowing only that the government has no intention of tolerating the ongoing rocket attacks against civilians in southern Israel.

"We intend to reassert and bolster deterrence in a way that will enable to operate in the perimeter along the Gaza border fence and better ensure the safety of soldiers operating on all sides of the Strip," he said, adding that Islamist group Hamas, which rules the coastal territory, "will not escape unpunished."

The remarks came as a new round of cross-border violence entered its fourth day on Tuesday, with Palestinian militants firing a rocket at the coastal city of Ashdod and Israel Air Force craft launching bombing sorties over Gaza.

As of Tuesday morning, an estimated 160 rockets and mortar shells had been fired at southern Israeli cities and smaller communities bordering the strip since hostilities erupted on Saturday, according to local media.

In response to rocket volleys fired throughout Monday which lightly injured dozens, Israeli aircraft targeted militant sites in Gaza in a series of strikes launched overnight, among them a weapons storage facility and two rocket launching sites. An Iron Dome anti-missile defense system reportedly shot down two projectiles heading to the town of Ofakim, while three others exploded in open areas near Sderot late in the evening.

Prime Minister Benjamin Netanyahu was expected to convene his forum of nine senior ministers on Tuesday to deliberate responses to the escalation, with some ministers hinting that a large-scale ground operation to quell the rocket fire was in the offing.

"Anyone with eyes in his head can see that an Israeli ground operation in Gaza is near at hand," Education Minister Gideon Sa' ar, a member of the security cabinet, told Israel Radio.

"We will choose the timing responsibly and level-headedly," he said, assessing the chances of reaching a cease-fire agreement with Gaza as low due to a bevy of militant factions who lob rockets in defiance of Hamas's instructions.

On Monday, Netanyahu began efforts to shore up international backing for a possible ground offensive in Gaza.

Addressing a group of 50 ambassadors in coastal Ashkelon, Netanyahu said, "The world must understand that Israel has the right and obligation to defend its citizens."

"We won't sit idly by in the face of daily attacks against our citizens and children. More than one million citizens have to live in a reality where they need to find shelter within 15 or 30 seconds when an air raid siren is sounded. None of your governments would accept such a situation. We do not accept such a situation, and I, as prime minister, am not prepared to accept this situation," he said.

A host of constraints, however, are likely to delay increased military action against Gaza in the near future.

A Tuesday report in the Hebrew-language Ma'ariv daily said that Egypt had threatened to recall its new envoy in Tel Aviv, Atef Salem, in the event of a ground operation in the coastal enclave.

Responding to complaints of residents of Israel's south that the military's response to the rocket fire is insufficient, Barak said Tuesday that Hamas and other militant faction have been " getting tough blows" via "correct, professional and methodical" military action.

He commended local leaders and citizens of the region for their resilience and ability to maintain daily routine "even when it is obvious that there is no 'quick fix' solution, at least not with a 'single stroke of the sword'. These things require an attitude of grit and endurance," Barak said.