Israeli Prime Minister Ehud Olmert said on Sunday at the start of the weekly cabinet meeting that Israel would respond firmly to rocket attacks from the Hamas-ruled Gaza Strip.

"The cabinet's position from the outset was that if there is rocket fire at southerners, there will be a response that will essentially be disproportionate," Olmert was quoted by local daily The Jerusalem Post as saying, shortly after four rockets fired from Gaza hit southern Israel on Sunday morning.

There have been sporadic rocket attacks by Gaza militants on southern Israeli communities and several Israeli air strikes in Gaza since a truce came into effect on Jan. 18 following a 22-day-long Israeli offensive in the Palestinian enclave.

"Two weeks have passed since Israel's decision to cease its fire in the Gaza Strip, and the truce was declared on two basic conditions: A complete halt in rocket fire and a stop to the smuggling of weapons to terror group through the Philadelphia Corridor," said the premier.

Those were the two conditions for the ceasefire and Israel knew that there was a considerable chance Hamas would continue with the rocket fire, he added.

"We won't return to the rules of the game that terror groups have tried to dictate and we won't be dragged into a never-ending shooting war," said Olmert, noting that Israel would not allow the rocket attacks to continue.

Olmert said he had instructed Israeli Defense Minister Ehud Barak to order the army to prepare a response.

"We won't give the terror groups warning as to when and how we'll react, but Israel will respond and act at the time and place of its choosing," said the prime minister.

Before the cabinet meeting, Israeli Foreign Minister Tzipi Livni called for a strong response to Sunday morning's rocket attacks.

"We must not try to reach a settlement with Hamas, we need to act against the group with might," she said. "Israel will respond, whether a Qassam hits its target or not, and that's how I will act as prime minister."

Barak also vowed a response, but he said Israel would act with discretion.

In election season, there is a lot of chatter by people who have never held a weapon and don't understand the conditions under which Israel must act, he said, noting that "We will respond in the right way to what is happening in Gaza."

"The professionals under my guidance will formulate a correct response, but we have to act with discretion and responsibility. Hamas was dealt a severe blow and it will be dealt one again, but the decision needs to be made by the experts," said the defense minister.