Israeli warplanes struck a guerrilla stronghold and three power stations across Lebanon on Tuesday in retaliation for Hezbollah guerrillas' killing of five Israeli soldiers in the past two weeks.

The attack left at least seven civilians wounded in the eastern Lebanese town of Baalbek, and large areas of Lebanon, including the capital Beirut and the southern cities of Sidon and Tyre, in darkness, witnesses said.

Israeli authorities said in a statement that a power station and a Hezbollah "headquarters" were destroyed in Baalbek, a center of Hezbollah activity.

A power station in the eastern part of the Lebanese capital and another one in Deir Nbouh in the far north were also struck.

"The army warns and cautions that a terrorist strike on Israeli territory will bring about a widening of the confrontation and a sharp response from Israel," said the Israeli statement.

The air attacks came after Israeli-Syrian peace talks broke down last month as Israel turned down a Damascus demand that Israel returns the occupied Golan Heights. Last week, the Israeli cabinet approved air raids on suspected Hezbollah guerrillas bases in the security zone Israel carved out in 1985 in south Lebanon.

The Tuesday air raids were in direct response to a series of Hezbollah attacks that killed five Israeli soldiers in two weeks, including a senior officer in Israeli-supported South Lebanese Army.

Israel has been defending its presence in the zone to protect its northern territory from guerrilla attacks. Hizbollah guerrillas have been fighting to drive the Israelis out.

Israeli Prime Minister Ehud Barak said he expects a withdrawal from the area by July under an agreement with Syria, the main power broker in Lebanon. But he has not said if a unilateral pullout will come without peace with Lebanon and Syria.

Many Israeli politicians have viewed the recent Hezbollah attacks as a Syrian attempt to put pressure on Israel. Hezbollah is supported by Iran, and Syria also has been believed to have control over it, but Syria has denied.