Israel Hits Back at PLO in Lebanon : Mideast: Palestinians are accused of trying to open a new front in Gulf War in support of Iraq.

Palestinians have opened up a new war front in Lebanon on behalf of Iraq, Israeli officials say, but Israel will treat the conflict as part of an old front in its war with Palestinians and hit back as it has before.

For the third day in a row Thursday, guerrillas peppered an Israeli-held buffer zone in south Lebanon with fire from short-range Katyusha rockets, and Israeli troops responded with artillery, helicopter and gunboat attacks.

Much of the Israeli shelling was directed at the Palestinian refugee camp at Rashidiyeh, south of the Lebanese city of Tyre, relief officials said. Fires reportedly broke out in the teeming enclave that is home to many followers of the Palestine Liberation Organization.

Officials in Jerusalem were quick to declare that Israel would strike back against any attack from Lebanon and not follow the policy of restraint that it has practiced in the face of long-range missile attacks by Iraq on Tel Aviv and Haifa. Israel has withheld retaliation for the missile attacks in deference to Washington’s concern that it might broaden the war against Iraq into a general Arab-Israeli conflict.

“Iraq is Iraq and Lebanon is Lebanon,” government spokesman Yossi Olmert said. “The same inhibitions do not apply.”

Israel maintains a border security zone inside Lebanon to discourage ground and artillery attacks on its northern frontier. The buffer zone, ranging from six to 10 miles wide, is patrolled by the South Lebanon Army, an Israeli-backed, Christian-led Lebanese militia. In the current outbreak of guerrilla activity, all of the Katyusha rockets have fallen inside the buffer area and none have reached Israel.

Early Thursday, a South Lebanon Army patrol ambushed and killed three guerrillas apparently trying to infiltrate Israel, authorities here reported.

Israel invaded Lebanon in 1982 in part to drive the PLO out of that unsettled country. After occupying parts of Lebanon for three years, the Israeli army withdrew but held onto the buffer zone. About 1,000 Israeli troops assist and direct the Lebanese militia in the zone.

Israeli officials say that the PLO has launched rockets into the buffer zone to show support for Iraq in its war with U.S.-led multinational forces in the Persian Gulf. Iraqi President Saddam Hussein has pressed for an end to Israel’s occupation of the West Bank and Gaza Strip, and his threats against the Jewish state have made him a hero to many Palestinians.

The PLO, the Israelis say, prefers to take action in Lebanon rather than trying to stage terrorist activities elsewhere to avoid damaging its dwindling relationships with countries in Europe and among such anti-Iraq Arab states as Egypt.

Besides the refugee camp at Rashidiyeh, Israel directed artillery fire on terrain east of the Lebanese city of Sidon, where PLO camps are reportedly located. In addition, Israeli troops shelled Shiite Muslim camps of the fundamentalist Hezbollah militia in the inland Bekaa Valley. Hezbollah frequently makes forays into the Israeli buffer zone, attempting to harass the South Lebanon Army and drive Israeli forces out.

Officials said there have been no casualties on the Israeli side in the security zone so far from the rocket volleys. Reports from Lebanon said that seven people were killed in the past three days of Israeli shelling.