The rocket attack was the first from Gaza since Thursday, said the Israeli military spokesman, who declined to be identified under army regulations. There was no claim of responsibility from any Palestinian militant group.
Also on Saturday, relations between Turkey and Israel remained tense, with Turkish Prime Minister Recep Tayyip Erdogan blasting Israel in an interview for turning the West Bank and Gaza Strip into an "an open-air prison."
Israel and Gaza's Hamas rulers stopped fighting in late January after a fierce three-week Israeli offensive meant to halt eight years of near-daily rocket fire from Gaza at southern Israel.
Nearly 1,300 Palestinians were killed in the fighting, about half of them civilians, according to the Palestinian Center for Human Rights. Thirteen Israelis were also killed, three of them civilians, according to the government
Since then, Palestinian militants have fired rockets sporadically toward Israel and killed one soldier on Tuesday. Israel has conducted retaliatory strikes and pounded border tunnels it says Hamas uses to smuggle in weapons from Egypt.
Without a political agreement to anchor the cease-fire, Gaza and Israel's southern region are expected to continue to be unstable. The biggest winners in the Gaza war, however, appear to be hard-liners on both sides who are likely to continue taking uncompromising positions.
On Friday, top Gaza Hamas leader Khalil al-Hayeh emerged in public for the first time since the war began to declare victory. In Israel, leading hawk Benyamin Netanyahu is the front-runner in elections just a week away.
Hamas has ruled out a long-term cease-fire with Israel if officials do not open sealed border crossings with the coastal territory. Israel is unlikely to do so while the militant group rules Gaz and holds captive Israeli soldier Gilad Schalit, who was seized in a cross-border raid in 2006.
President Barack Obama's Mideast envoy, George Mitchell, completed his first visit with Israeli and Palestinian leaders on Friday evening, but little substantive work can be done until Israel completes its elections.