TYRE, Lebanon - Hezbollah launched a new kind of rocket Friday that made its deepest strike into Israel yet, rattling Israelis as their warplanes and artillery blasted apartment buildings and roads gunning for guerrillas.

Lebanese officials said about 12 civilians died in the day's fighting; Israel said it killed 26 militants, raising to about 230 the total number killed in the campaign.

Hezbollah's launching of the new weapon unnerved Israelis, 500,000 of whom are already living in northern shelters because of rocket bombardments. The rocket firing was also likely to escalate a conflict now in its 18th day, with Secretary of State Condoleezza Rice heading back to the Middle East this weekend to make a second attempt to resolve the crisis.

The guerrillas said they used the Khaibar-1- named after the site of a historic battle between Islam's Prophet Muhammad and Jewish tribes in the Arabian peninsula- to strike the Israeli town of Afula.

"With this, the Islamic Resistance begins a new stage of fighting, challenge and confrontation with a strong determination and full belief in God's victory," Hezbollah said in a statement.

Five of the rockets crashed into empty fields outside Afula, causing no injuries. Still, Israel deployed a Patriot interceptor missile battery north of Tel Aviv, believing the area could be in range of Hezbollah's barrages.

Israel said the Khaibar-1 rockets were renamed, Iranian-made Fajr-5s. They have four times the power and range of Katyusha rockets, making them able to hit Tel Aviv's northern outskirts.

Hundreds of Katyushas have hit northern Israel in the current fighting, including 96 on Friday, one of which hit a hospital. The Afula strike came two days after Hezbollah leader Sheik Hassan Nasrallah vowed his guerrillas would fire rockets beyond Haifa, Israel's third-largest city, which has been hit repeatedly in the conflict.

Rice's second trip to the region comes as diplomatic efforts are solidifying into two sharply divided camps. Most agree on the idea of bringing international forces into the south to end Hezbollah's decade-long free rein here - but still unresolved is how and when.

The United States, backed by Britain, wants the force to be part of a broad package that will disarm guerrillas along the border and move in the Lebanese army to end the Hezbollah threat to Israel once and for all. It says it won't press for a cease-fire until such an agreement is reached.

Many Europeans and Arab countries are increasing the pressure for an immediate cease-fire first, followed by a plan to tackle the complicated issues of a force to curb the Shiite guerrillas.

The deadlock allowed the offensive to persist with a new dimension of destruction emerging - the environment.

Beaches in Beirut were black with oil spilled from a power station that was blasted by Israel two weeks ago and was still burning. In the south, rescue workers dug through the rubble of bombed houses, looking for bodies.

Late Friday, the Israeli army said it killed 26 Hezbollah guerrillas in fighting for the Shiite town of Bint Jbail. The army did not report Israeli casualties, but Israel Radio said six soldiers were wounded.

Hezbollah has verified 35 guerrilla casualties. The competing claims could not be resolved independently.

Hezbollah said its guerrillas attacked Israeli troops on a ridge overlooking Bint Jbail and in Maroun al-Ras, a nearby villages that Israeli troops overran last weekend. The guerrillas said five Israeli soldiers were wounded.

Eight Israelis died fighting for control of Bint Jbail on Wednesday, the highest toll of the campaign. Bint Jbail had the largest Shiite community along the border; it was known as the "capital of the resistance" during Israel's 1982-2000 occupation because of its vehement support for the Shiite Hezbollah.

The Israel army said a half-million Israelis were living in shelters in northern Israel. U.N. humanitarian chief Jan Egeland told CNN that 800,000 Lebanese had fled or were caught in crossfire.

A top U.N. peacekeeping official said he thought the war could continue until the end of August and voiced fears Israel would flatten Lebanon's southern villages and destroy the port of Tyre "neighborhood by neighborhood" if Hezbollah rockets keep slamming into the Jewish state.

At U.N. peacekeeping headquarters in Naqoura, barely a stone's throw from Israel, political affairs officer Ryszard Morczynski said Tyre would become a target of intense Israeli attacks because Hezbollah was firing rockets from the city's suburbs into Israel's northern port, Haifa.

The Israeli offensive began after Hezbollah guerrillas killed three soldiers and captured two others in a cross-border raid into Israel. The war with Hezbollah opened a second front for Israel, which was already battling Palestinians in Gaza after Hamas militants seized a soldier in a cross-border raid June 25.

Israeli tanks and troops pulled back to the Israel-Gaza border Friday after an unusually deadly incursion that killed 30 Palestinians over three days. The army said the withdrawal was temporary.

On Israel's border with Lebanon, the United Nations decided to move 50 unarmed observers from their posts to the better-protected positions of 2,000 lightly armed U.N. peacekeepers after an Israeli bomb killed four observers this week.

With medicine, food and shelter trickling into the war zone in southern Lebanon, Egeland called for a three-day truce to let help aid get in and enable thousands of civilians trapped in the heat of the battle to get out ¡ª a call that got no response.

In Washington, President Bush and British Prime Minister Tony Blair said they want an international force dispatched quickly to southern Lebanon. But they said any plan to end the fighting must address the long-term issue of disarming Hezbollah.

"This is a moment of intense conflict in the Middle East," Bush said. "Yet our aim is to turn it into a moment of opportunity and a chance for broader change in the region."

In Beirut, Hezbollah signed onto a peace plan put together by the prime minister that calls for an international force and the Lebanese army to move into south Lebanon ¡ª a step that could mean the withdrawal of guerrillas from the border and eventual disarming.

But the plan requires not only a cease-fire first ¡ª but also a prisoner exchange and a resolution of several disputes between Israel and Lebanon that Beirut says fuel Hezbollah's strength and gives it a reason to continue fighting.

A team of European Union leaders praised the proposals and the show of unity in Lebanon's government, which has been paralyzed by divisions over the crisis. "We think (the plan) forms a good basis for a regional agreement," said Finnish Foreign Minister Erkki Tuomioka, whose country holds the EU presidency.

French President Jacques Chirac said his country will press for the rapid adoption of a U.N. Security Council resolution calling for an immediate cease-fire, increasing the pressure on the United States and Israel.

In southern Lebanon, Israeli missile strikes and artillery rained down around towns and roads targeting rocket sites and buildings believed connected to Hezbollah but wreaking destruction in populated areas.

One airstrike flattened a house in the village of Hadatha, and six people inside were believed dead or wounded, the Lebanese state news agency reported. Hezbollah's al-Manar TV said all six were dead.

Missiles destroyed three buildings in the village of Kfar Jouz near the market town of Nabatiyeh, apparently targeting the apartment of a Hezbollah activist. A Jordanian was killed in a nearby house, and the blasts collapsed a shelter, killing a Lebanese husband and wife.

Three women were killed in strikes on their homes in other southern villages, security officials said. A wounded woman was rushed to the hospital in the village of Ain Arab, and more people were believed trapped in the debris of a destroyed building there.

An explosion, believed to be from Israeli artillery, hit a convoy evacuating villagers from Rmeish, lightly wounding a driver and a Lebanese cameraman for German TV news. Another strike hit a potato truck and a nearby car, wounding three.

At least 445 people have been killed in Lebanon in the fighting, most of them civilians, according to a Health Ministry count Friday based on bodies taken to hospitals. But Lebanon's health minister estimated Thursday that as many as Lebanese 600 civilians have been killed, with other victims buried in rubble.

On the Israeli side, 33 soldiers have died in fighting, and Hezbollah rocket attacks on northern Israel have killed 19 civilians, the Israeli army said.