Israeli warplanes bombed more Palestinian guerrilla headquarters in Lebanon today and the Palestinians unleashed new long-range rocket and artiller attacks on Israeli civilian centers. As they did, U.S. special envoy Philip C. Habib met with Prime Minister Menachem Begin to seek a cease-fire in the expanding Israeli-Palestinian warfare.

[The Israeli military command said its troops struck inside southern Lebanon early Monday morning to attack Palestinian positions near Nabatiyeh, Reuter reported. It was the first ground attack in the 10-day Israeli offensive against Palestinian targets. The military spokesman said a number of Palestinian guerrillas were killed and that six Israeli soldiers were injured.]

[In Beirut, the Palestine Liberation Organization said Israeli troops tried to land from two warships off the Lebanese coast but were driven off, Reuter reported. The PLO made no mention of casualties.]

A 14-year-old Israeli youth was killed when a barrage of Katyusaha rockets fell on the northern Israeli development town of Kiryat Shemona. Israeli authorities reported that 23 other residents of the town were injured, including the youth's mother, who was in critical condition.

Israeli fighter-bombers pounded Palestinian regional command headquarters throughout southern Lebanon.

The recent exchanges have caused nearly 250 deaths and another 900 injuries in Lebanon, most of them Palestinian and Lebanese civilians, according to reports from Beirut. At the same time, Sraeli authorities have reported four Israeli civilians killed and about 50 wounded.

Palestinian positions in Nabatiyeh, Tyre and the crusader-era Beaufort Castle were among those bombed in today's raids, the Israeli Army command said. An Israeli military spokesman and Israeli pilots reported "accurate hits" on guerrilla deployments and artillery positions, including 130mm gun emplacements that he said had earlier in the day fired salvos into the Israeli coastal resort city of Nahariya.

Habib has been ordered by President Reagan to break off his diplomatic shuttle attempting to defuse the crisis over Syrian missiles in Lebanon and concentrate instead on the related goal of a cease-fire between Israel and the Palestinians. He met twice today with Begin and other top Israeli diplomatic and military officials.

In a one-hour morning session, Habib called on both sides to stop shooting immediately so that agreement for a more lasting end to the fighting can be sought, perhaps with Syria playing a role.

An official in Begin's office said the prime minister and his key advisers haeld out little hope for a negotiated end to the hostilities and that there is growing pressure within Begin's inner circle for resolving both the Palestinian problem and the Syrian missile crisis by launching a wider conflict against Syria on Lebanese soil.

Other informed aides to the prime minister said that Begin is taking seriously promises he made during his recent reelection campaign that if returned to another four-year term, he would put a stop to Palestinian guerrilla shelling of northern Israeli civilian settlements.

[In Washington, Secretary of State Alexander M. Haig Jr. made clear the Reagan administration's hopes that the talks between Habib and Begin will produce "some tamping down of the situation" before the United States makes a decision Tuesday whether to release F16 fighter-bombers whose delivery to Israel was suspended after the Israeli bombing of an Iraqi nuclear reactor June 7.]

[The administration, which had planned to lift the suspension last Friday, pulled back hastily at the last minute following the Israeli attacks on Beirut. At the time, however, it refused to link its action to the bombing.]

[Haig, interviewed on the television program "Issues and Answers" (ABC, WJLA), persisted in the refusal to link Israel's tactics in Lebanon and the F16 deliveries.]

["We want them (the Israelis) to consider our interests as well as their own," Haig said. While he made vague mention of recent U.S.-Israeli discussons "clearing the air," Haig also stressed that no "specific understandings" have been reached about future Israeli use of U.S.-supplied weapons.]

Israeli sources said the prime minister told Habib in Jerusalem that Israel did not initiate the crossborder exchanges and is not interested in letting the conflict escalate into a wider war of attrition. However, Begin told Habib that Israel is unwilling to stand by and allow its civilians to be killed by the Palestinians.

The Israeli Army's chief of military intelligence, Maj. Gen. Yehoshua Saguy, aid today that a motive of Israel's massive bombing raids Friday in densely populated quarters of Beirut was to attempt to generate Lebanese civilian resentment against the presence of Palestinian guerrillas there.

"I would say at least they have something to think about now. . . . We're trying to make people think about the consequences of this intensive [Palestinian] fire," Saguy said in a briefing for foreign correspondents.

It was the first time that a senior Israeli military official publicly said that an expected benefit of the Beirut raids was to turn the Lebanese civilians there against the presence of Palestinian guerrilla headquarters. Previously, government spokesmen had said the purpose was to disrupt the Palestine Liberation Organizaton's political infastructure and that the various PLO factions had unfortunately been situated in civilian population centers.