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.