JERUSALEM -- In the first border flare-up of its kind in four months, a Katyusha rocket fired from Lebanon struck northern Israel on Sunday, triggering a heavy artillery barrage from Israeli forces in response. No casualties were immediately reported on either side of the frontier.
The United Nations force in southern Lebanon urged restraint on both sides and said it was in contact with the Israeli and Lebanese authorities.
It was not immediately clear who fired the rockets, at least one of which struck outside the Israeli border town of Kiryat Shmona. Residents reported loud explosions as the projectile landed in an open area west of town.
Israel said a total of five rocket launches in its direction were detected. Lebanon's state-run National News Agency, or NNA, reported that at least two of them apparently fell short of their intended targets in Israel, landing instead in Lebanese territory, about six miles from the town of Marjayoun.
Israel fired back dozens of artillery shells, which it said were aimed at the source of the rocket launches. NNA reported that at least 20 shells fell on several rural farming hamlets.
A spokesperson for Israel's military called the attack "inexcusable and blatant," and Defense Minister Moshe Yaalon reminded the Lebanese government that Israel holds it responsible for hostile actions originating in Lebanese territory.
Israel filed a complaint to UNIFIL, the U.N. interim force.
In the wake of the 34-day war between Israel and the Lebanese Shiite militia Hezbollah in 2006, the border has been largely quiet. The U.N., Lebanese authorities and Israel have all worked to prevent escalation of any incident.
Two weeks ago, an Israeli soldier was killed by shots fired over the border by a sniper from the Lebanese armed forces, but hostilities went no further after indications that the shooting was isolated and unauthorized.
The mayor of Kiryat Shmona, Nissim Malka, told reporters that town officials were in touch with the Israeli military, but that residents had not been given any special security instructions, as they would be in the event of any serious attack.