Israel faces invisible enemy in southern Lebanon

BEIRUT, Aug 2 (Reuters) The thump of rocket-fire echoes through the air in southern Lebanon, but a glance at the rugged hillsides reveals only olive trees rustling in the breeze. No one sees rockets overhead. No gunmen walk village streets.

Israel is fighting a virtually invisible enemy -- highly trained Hizbollah fighters who are at home in south Lebanon's hillsides and caves, able to fire rockets then melt away.

It is fighting a Shi'ite Muslim guerrilla force, which, far outclassed by Israeli air power and technology, relies on its knowledge of the terrain, support from the mainly Shi'ite locals and, when ground forces get involved, ambush.

A cross-border raid on July 12 in which two Israeli soldiers were captured by Hizbollah -- deemed a terrorist organisation by Washington -- sparked an immediate Israeli response.

Israeli aircraft hammer hillsides or nearby roads, bridges and villages often just moments after Hizbollah rockets are fired. But as Israel's killing of 54 civilians in a raid on the village of Qana on Sunday showed, targets are not easy to find from the air and cost Israeli lives to reach by land.

''Hizbollah are playing very smart guerrilla rules. They know they cannot challenge Israel in open combat, with its air power, so they wait until it moves deeper into Lebanon, where they know the terrain, and ambush,'' said Timur Goksel, former spokesman for the U N peacekeeping force in southern Lebanon.

''That is why Israel is not going too far inside Lebanon. It has the power but it is aware of the traps.'' When Hizbollah pulled out of Maroun al-Ras in the second week of the war, they booby-trapped their homes in the border village, killing one Israeli soldier and wounding three who stepped on the rooftops, a Hizbollah source said.

A Hizbollah ambush at dawn last week killed eight troops and wounded 22 in the nearby stronghold of Bint Jbeil, which Israel managed to surround but was unable to immediately capture.

Up to 6,000 Israeli troops, with tanks and air cover, are now battling Hizbollah fighters on five fronts in south Lebanon. But while Israel has punched through the border at various points, it has so far avoided a full-scale invasion it knows from experience could mire it in years of fighting.

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