JERUSALEM: Gaza militants launched two rockets into southern Israel early Sunday, drawing a threat of “disproportionate” military retaliation from Israel’s prime minister and further straining a cease-fire that ended Israel’s devastating Gaza offensive two weeks ago.

There were no casualties from the rockets, though one projectile landed near a kindergarten in a community near Gaza, said a police spokesman, Micky Rosenfeld.

The recent Israeli offensive was aimed at halting years of rocket attacks, and the military declared a cease-fire on Jan. 18 after declaring its goals had been achieved.

But on Sunday the rockets, which followed sporadic rocket fire and the killing of an Israeli soldier in a border bombing attack last week, illustrated the difficulties of achieving a complete end to the attacks. Despite years of efforts, Israel’s high-tech military still has not found a solution to stopping the projectiles.

Speaking to his cabinet on Sunday, Israel’s outgoing prime minister, Ehud Olmert, said Israel would respond “when and where we choose.”

The government’s position, Olmert said, is that “if there is shooting at residents of the south, there will be an Israeli response that will be harsh and disproportionate by its nature to the shooting at residents of Israel and at our forces.”

Hamas has not taken responsibility for any of the new attacks, which have been claimed by smaller militant groups. But Israel says it holds Hamas, which has ruled Gaza since seizing power in June 2007, responsible for all attacks emanating from Gaza.

The rocket strikes come just over a week before Israel holds a parliamentary election. Tzipi Livni, the foreign minister and one of the leaders behind the operation, has replaced Olmert as head of the centrist Kadima party and is the only serious challenger to the front-runner, the hard-line Likud leader, Benjamin Netanyahu, according to recent opinion polls.

Netanyahu has been campaigning on a platform that calls for a tough stance against Hamas, and he stands to benefit if Israelis conclude that the offensive failed to achieve its goal of making residents of southern Israel safer.

Since ending the offensive, Israel has conducted retaliatory strikes and pounded tunnels Hamas uses to smuggle in weapons from Egypt. Israeli forces have also shot and killed three men whom Palestinians identified as farmers along the Gaza-Israel border.

One of Israel’s main concerns is that Hamas could continue smuggling weapons into Gaza through tunnels under the Egypt border. Israel is pushing Egypt to do more to crack down on the flow of weapons, and internationally backed anti-smuggling efforts are at the center of attempts to win a lasting cease-fire in Gaza.

Gaza is still struggling to recover from the punishing three-week offensive, which left swaths of the territory damaged and nearly 1,300 people dead, more than half of them civilians, according to Gaza officials. Thirteen Israelis were killed, including three civilians.

Hamas officials in Cairo were set to meet with Egyptian mediators on Sunday. The Palestinian president, Mahmoud Abbas, will meet Egyptian officials in Cairo on Monday. The official Palestinian news agency, Wafa, said that a visit by Abbas to the Czech Republic planned for Monday would have to be rescheduled.