A rocket fired from Lebanon toward Israel fell short, wounding a Lebanese woman, a senior Lebanese military official said Monday.
The attack comes nearly two weeks after rockets fired from Lebanese territory hit the Jewish state for the first time in two years.
It follows rising concerns that conflict in neighboring Syria may spill across the border.
This latest rocket was fired late Sunday from the southern village of Majdal Silim and hit a home in Houla, another village close to the border, the official said on Monday.
He said an investigation is under way, speaking anonymously in line with regulations.
Early Monday, at least four warplanes were seen flying at high altitude over southern Lebanon and the Lebanese capital Beirut.
Israeli warplanes and drones frequently fly over Lebanon but it was not clear if these flights were related to the rocket attack.
The southern border has been tense, but largely quiet, since Lebanon's Hezbollah group and Israel fought a deadly 34-day war in 2006. During the fighting, Israel bombed Hezbollah's strongholds in Lebanon, and the militant group barraged northern Israel with nearly 4,000 rockets.
About 1,200 Lebanese and 160 Israelis were killed in the conflict, which ended with a UN-brokered truce that sent thousands of Lebanese troops and international peacekeepers into southern Lebanon to prevent another outbreak.
There have been several rocket launches since the 2006 war, but Hezbollah has not claimed responsibility for any of them. Smaller Palestinian factions, some linked to al-Qaeda, have claimed to have launched rockets on several occasions.
The latest rocket launch into Israel, the first in two years, happened in November. There were no casualties.
Sunday's launch came two days after a roadside bomb hit a UN vehicle in southern Lebanon, wounding five French peacekeepers and a Lebanese bystander.
France's foreign minister said Sunday that France had "strong reason" to believe that Syria was behind the blast. Alain Juppe told RFI radio that Paris believes Hezbollah was also involved, but has no proof.
The two incidents come amid fears that violence in neighboring Syria might spread into Lebanon. President Bashar Assad is facing international condemnation for brutally crushing an uprising against his rule, and France has been among his fiercest critics.
Damascus dominated the tiny Mediterranean nation for three decades until it withdrew its troops in 2005. Assad's government maintains close ties with Hezbollah, which also receives backing from Syria's ally Iran.
