MARJAYOUN, Lebanon (AP) _ Shiite Muslim guerrillas attacked an Israeli military post in south Lebanon on Sunday and the Israelis retaliated by shelling two villages, security sources said.

The Islamic Resistance, the military wing of the pro-Iranian fundamentalist Hezbollah, or Party of God, claimed responsibility for the attack in a statement issued in Beirut. It said eight Israeli soldiers were killed or wounded.

But the security sources, who spoke on condition of anonymity, said there were no Israeli casualties.

One source said the guerrillas infiltrated Israel's self-styled ''security zone'' and fired several rocket-propelled grenades at the military post in the village of Kawkaba.

Israeli artillery subsequently shelled the villages of Dallafeh and Abu Rashed, the sources said. There was no immediate word of casualties in the villages.

Hezbollah guerrillas recently have intensified their attacks in south Lebanon, where Israel maintains a 440-square-mile ''security zone'' as a buffer against attacks on its northern settlements.

The zone is protected by some 1,200 Israeli soldiers and their 3,000-man militia ally, the South Lebanon Army.

Since May 18, at least 29 people have been killed and 79 wounded in the attacks and in Israeli air strikes in the area.