Hezbollah guerrillas attacked an Israeli military position in a disputed part of the south Lebanon border on Friday, provoking swift Israeli airstrikes on suspected Hezbollah sites, Lebanese security officials said.

Hezbollah said in a statement that its bombardment of rockets and shells was in retaliation for the killing by Israel this week of a Lebanese person who went missing around the disputed border area of Chebaa Farms on Wednesday. Hezbollah added that it had attacked the same Israeli position that fired the shots which killed the person.

The Israeli army said Hezbollah fired a barrage of rockets at an Israeli military position in Chebaa Farms.

Shortly afterward, Israeli planes bombed suspected Hezbollah targets along south Lebanese border, said a Lebanese security official, speaking on condition of anonymity because he was not authorized to talk to the media.

The official said the planes fired at least four missiles at targets near the villages of Kfar Chouba, Kfar Hamam and Halta in the Chebaa Farms area. Israeli artillery also fired at sites where the Hezbollah rockets were thought to have come from. There was no immediate word on casualties.

On Wednesday, Israel said its troops fired at, and apparently hit, a man who crossed the U.N.-demarcated border. Lebanon says the victim was 15-year-old shepherd Ibrahim Youssef Rhayyel, while Israel says the victim was an armed man with binoculars. The bullet-ridden body was found Thursday on the Lebanese side of the border.

Hezbollah insisted Rhayyel was a civilian and its leader, Sheik Hassan Nasrallah, warned Wednesday that if he were found dead, the guerrillas would "punish the killers without hesitation."

In its statement Friday, Hezbollah said the Israeli outpost took "direct hits" from the shelling, but the group did not mention any casualties.

Chebaa Farms is frequently the scene of fighting between Hezbollah and Israeli troops. A tiny parcel of land held by Israel, Lebanon claims the territory and Hezbollah has vowed to liberate it. But U.N. cartographers say it belongs to that part of Syria which is occupied by Israel. It lies only a few miles from Israel proper.

In November, fighting in Chebaa Farms left four Hezbollah guerrillas dead and 11 Israeli soldiers wounded.

The last flare-up in cross-border violence was in late December when rockets fired from Lebanon crashed in the northern Israeli town of Kiryat Shmona, damaging property but causing no casualties. Israel retaliated with an airstrike against a radical Palestinian guerrilla base on a hill south of Beirut.