Israeli warplanes struck suspected guerrilla positions in southern Lebanon (search) after rocket and artillery exchanges early Friday with the Lebanese Hezbollah (search) group in the disputed Chebaa Farms (searchborder area, Lebanese security officials said.

Less than two hours after clashes between Israeli and Hezbollah forces erupted at daybreak, two Israeli fighter jets made two runs, firing at least one missile in each on guerrilla-controlled territory just outside the Chebaa Farms, the officials said.

The airstrike, the second since Wednesday, appeared to be aimed at the source of guerrilla rocket fire.

The rocket and artillery exchanges centered near the Israeli position of Roueissat el-Alam. Israeli artillery shells hit in the hills above the village of Kfar Chouba in southeastern Lebanon, said the officials, speaking on condition of anonymity.

There was no immediate word on casualties.

Hezbollah officials said the battle began when Israeli troops tried to infiltrate guerrilla-controlled territory and were ambushed. There was no immediate comment from Israel on the fighting, which came two days after guerrilla shooting of anti-aircraft fire led to an Israeli airstrike in southern Lebanon.

South Lebanon has been largely quiet since Israel withdrew its army from the area in 2000 after an 18-year occupation. But Israeli forces since have repeatedly clashed in Chebaa Farms with Hezbollah, the Syrian- and Iranian-backed Shiite Muslim militant group that led a guerrilla war against the occupation.

The Chebaa Farms is uninhabited farmland on the foothills of Mount Hermon near the country's southeastern border. Israel captured the territory when its forces seized Syria's Golan Heights in the 1967 Middle East war. Lebanon, backed by Syria, claims the territory as its own. The United Nations says the region is Syrian, and that Syria and Israel should negotiate its fate.

Israel and the United States regard Hezbollah as a terrorist group, but Lebanon regards it as a legitimate resistance movement against Israeli occupation of Arab lands.

On Thursday, Lebanon's Foreign Ministry complained to the United Nations about Israeli overflights and the Israeli airstrike a day earlier on a suspected guerrilla hideout in southern Lebanon.

Wednesday's airstrike, the first on Lebanon since March, came after Hezbollah guerrillas fired anti-aircraft guns at Israeli warplanes flying over Lebanon.

Israel's military accused Hezbollah of deliberately aiming at targets on its territory under cover of anti-aircraft fire. It said shrapnel from the anti-aircraft shells hit an Israeli border community, causing no casualties.