Security sources confirmed the strike, citing that the Israeli Air Force struck six targets in Gaza during the evening hours.
The targets included a Hamas stronghold, and several tunnels on the Philadelphi Route. According to the sources, the fire triggered several explosions, indicating that Hamas as resumed its arms smugglings.No casualties were reported.
One attack was on a security headquarters in a village in central Gaza that residents said had been vacated after Israel telephoned warnings to Palestinians to leave buildings that housed any weapons.
About a dozen rockets and mortar bombs fired from Gaza struck Israel on Sunday. Three Israelis were wounded, including two soldiers and the first Israeli civilian hurt since a Jan. 18 truce ended Israel's 22-day offensive in the coastal enclave. They suffered shrapnel injuries, medics said.Theal-Aqsa Martyrs Brigades, a group belonging to Palestinian President Mahmoud Abbas' Fatah faction, said it fired some of the rockets, but not all were claimed.
Israeli leaders have taken a hard line against rocket fire in the run-up to a Feb. 10 national election, which opinion polls predict right-wing leader Benjamin Netanyahu will win.
"The government's position was from the outset that if there is shooting at the residents of the south, there will be a harsh Israeli response that will be disproportionate," Olmert, who is not a candidate, said at the weekly cabinet meeting.
"We will act according to new rules which will ensure that we will not be drawn into a war of incessant shooting on the southern border, which would deprive the residents of the south of a normal life," he said, without elaborating.
Palestinians in the southern Gaza town of Rafah, not far from the village targeted, received recorded voice messages by telephone warning "everybody who is near any place used for terror or weapon storage facility or tunnels, should evacuate the area immediately."
Similar warnings have preceded Israeli attacks in the past.
'Decisive and strong response needed'
A spokesman for the Hamas government in the Gaza Strip condemned what he described as Olmert's "aggressive statement".
But the spokesman, Taher al-Nono, also urged all Palestinian factions to "respect the national consensus" on the ceasefire the Islamist group declared two weeks ago after Israel announced it was halting the Gaza offensive.
Israel was criticized internationally for the deaths, according to the Hamas-run Health Ministry in Gaza, of more than 1,300 Palestinians, including at least 700 civilians.
Critics said Israel had responded disproportionately, in its air and ground offensive in heavily populated areas, to cross-border rocket attacks over eight years that killed 18 people. Ten Israeli soldiers and three civilians were killed in the Gaza campaign.
Israel said Hamas militants bore responsibility for civilian deaths in Gaza by operating inside its towns and refugee camps.
Since the truce, in addition to Sunday's injuries, an Israeli soldier was killed and three others were wounded when a bomb exploded next to their patrol. Israeli air strikes since Jan. 18 have killed three Palestinians and wounded 10.
Egypt has been trying to broker a long-term ceasefire that would end Hamas weapons smuggling into Gaza and also lead to a reopening of Gaza border crossings, one of Hamas' main demands.
Olmert's comments were echoed by Foreign Minister Tzipi Livni, a candidate for prime minister who trails Netanyahu in opinion polls ahead of the election whose campaign has focused on Israel's tensions with Islamist Hamas.
Livni has replaced Olmert as head of the ruling centrist Kadima party since he quit the government in a corruption scandal in September. He has remained caretaker prime minister until a new government is formed after the election.
"Israel will respond," said Livni. "This is my position. It was clear before, during and after the operation, and this is how I will conduct myself as prime minister."
Netanyahu said Israel should make "a decisive and strong" response to the latest rockets. "No matter how strong the blows that Hamas received from Israel, that's not enough," he said.