The rocket strikes come just over a week before Israel holds a parliamentary election, and could influence the outcome by making the Gaza offensive appear less successful. That could erode support for candidate Tzipi Livni, the foreign minister and one of the leaders behind the operation. Livni has replaced Olmert as head of the centrist Kadima party and is the only serious challenger to the front-runner, hardline Likud leader Benjamin Netanyahu, according to opinion polls.

Netanyahu has been campaigning on a hardline 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 who Palestinians identified as farmers along the Gaza-Israel border.

One of Israel’s concerns is that Hamas could continue smuggling weapons into Gaza through tunnels under the Egypt border. The smuggling allowed the group to obtain longer-range rockets that now have about one-eighth of Israel’s population in range. 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 struggling to recover from the three-week offensive, which left about 1,300 people dead. Thirteen Israelis were killed, including three civilians.