JERUSALEM -- Israeli jets and artillery pounded Palestinian and Lebanese guerrilla targets in Lebanon yesterday after rockets hit an army base in northern Israel. It was the harshest military response by Israel since it withdrew its forces from southern Lebanon six years ago, the military said.
In daylong fighting, Israeli forces exchanged fire with guerrillas from the Iranian-backed Hezbollah group along the length of the border with Lebanon, and residents in northern Israeli communities were ordered into bomb shelters as mortars and rockets fell in the area.
A cease-fire was mediated by U.N. peacekeepers at the request of the Lebanese government, the army said.
The flare-up followed Friday's killing in Lebanon of a leader of the militant Islamic Jihad group and his brother in a car bombing in the southern town of Sidon, an attack the group blamed on Israel.
Early yesterday, six to eight Katyusha rockets were fired from Lebanon at an Israeli military vehicle and two landed in an army base, slightly wounding a soldier, said Maj. Gen. Udi Adam, chief of the Israeli army's northern command.
The base was on Mt. Meron, about five miles from the Lebanese border, a target deeper in Israel than army positions previously attacked by Hezbollah.
Israeli aircraft responded with attacks on two bases in Lebanon of the Popular Front for the Liberation of Palestine-General Command, a radical group based in Damascus, Syria.
A militant was killed and five were wounded in an air strike on one base in Sultan Yacoub in the eastern Bekaa Valley, about three miles from the Syrian border, Lebanese officials said. A second base was hit outside Naameh, 12 miles south of Beirut.
The army said one of the bases, consisting of tunnels dug into the hills, was used to store arms and ammunition.
Adam said that after an Israeli soldier was wounded by sniper fire from Lebanon near a border outpost at Kibbutz Manara and guerrillas began firing over a wide area, the army responded by attacking more than 20 Hezbollah posts.
An army statement said artillery and air strikes targeted Hezbollah positions in response to machine-gun fire, mortar and Katyusha rocket attacks against Israeli army positions and communities along the frontier.
"Our response was the harshest and most severe since the withdrawal" from Lebanon, Adam said.
Hezbollah, whose forces control the Lebanese side of the border, linked the flare-up to Friday's killing of the Islamic Jihad leader and his brother.
"The Zionist enemy, who committed the crime of assassinating the two martyrs, alone bears responsibility for this dangerous escalation," the group said in a statement. "It knows that its crimes would lead to retaliation."
Adam said the army "has nothing to do with this liquidation" and that Israel was routinely blamed for violence in Lebanon. He called on the Lebanese government to assert control of its side of the border.
Israeli Prime Minister Ehud Olmert warned that Israel would "strike a very painful blow at anyone who tries to disrupt life in the north of the country." He added that Israel's response was "an important warning to Palestinian elements in Lebanon of what they may expect if this goes on or if such things recur."
Yesterday's violence was the worst witnessed along the border since November.
Lebanon's south had been relatively calm since Israel's army withdrew from a buffer zone inside Lebanon in 2000.
The United States and the United Nations have been pressuring Lebanon to implement a 2004 U.N. Security Council resolution that calls for the disarmament of all armed groups in Lebanon, including Hezbollah and radical Palestinian groups.
But the Lebanese government considers Hezbollah, labeled a terrorist group by the United States and Israel, a legitimate resistance movement fighting Israeli occupation of Lebanese territory.
Joel Greenberg writes for the Chicago Tribune. The Associated Press contributed to this article.