Two rockets were fired into northern Israel from Lebanon on Friday, and Israel's army responded with artillery fire, Lebanon's news agency and security sources said, adding it was unclear who was behind the initial attack.
Southern Lebanon is a stronghold of Hezbollah, a Shi'ite Muslim group that battled Israel seven years ago and is engaged in Syria's civil war in support of President Bashar Assad; but there are also Palestinian groups in the same area.
Lebanon's news agency NNA said the rockets were fired towards "occupied territories" at 6.30 a.m. from the Hasbaya area in Lebanon.
There have been several exchanges across the border in the past year.
In December, rockets launched from Lebanon struck northern Israel, provoking a response across a border that had been largely quiet since a war in 2006. In August, Brigades of Abdullah Azzam, an organisation linked to al Qaeda claimed a rocket barrage from Lebanon.
An Israeli military spokeswoman said a lone rocket launched from either Lebanon or Syria landed in Israel's far north ending up in an open area near a farming community close to the border with Lebanon. The army responded with artillery fire, she said.
There were five rockets fired in total from southern Lebanon, Lebanese security sources said. Two entered Israel, one fell into Lebanese territory and two more were intercepted.
An Israeli military spokeswoman confirmed that Israel responded with artillery fire. Israel shot back around 25 shells, the Lebanese security sources said.
Israeli Chief military spokesman Brigadier-General Motti Almoz said a rocket fell near Kibbutz Kfar Yuval and that the military was checking for more details on the source of the firing. There were no casualties or damage.
Palestinian militants in the Gaza Strip have launched hundreds of rockets into Israel since the start of an Israeli offensive four days ago, but Kfar Yuval is almost certainly out of range of those rockets.
At least 82 Palestinians, most of them civilians, have been killed in the offensive, which Israel says it launched to end persistent rocket attacks on civilians. Some rockets have reached Tel Aviv, Jerusalem and other cities.
Reporting by Sylvia Westall in Beirut and Ori Lewis in Jerusalem; editing by Ralph Boulton