BEIRUT, Lebanon — Hezbollah rammed an Israeli warship with an unmanned aircraft rigged with explosives Friday, setting it ablaze after Israeli warplanes smashed Lebanon's links to the world one by one and destroyed the headquarters of the Islamic guerrilla group's leader.

The attack on the warship off Beirut's Mediterranean coast — which left four sailors missing — was the most dramatic incident on a violent day in the conflict that erupted suddenly Wednesday and appeared to be careening out of control despite pleas from world leaders for restraint on both sides.

"You wanted an open war and we are ready for an open war," Hezbollah leader Sheik Hassan Nasrallah said in a taped statement. He vowed to strike even deeper into Israel with rockets.

In another maritime strike, Israel said that a Hezbollah rocket barrage missed its target and struck a civilian merchant ship. They did not know the nationality of the ship, or whether there were casualties.

Israel again bombarded Leba- non's airport and main roads in the most intensive offensive against the country in 24 years. For the first time it struck the crowded Shiite neighborhood of south Beirut around Hezbollah's headquarters, toppling overpasses and sheering facades off apartment buildings. Concrete from balconies smashed into parked cars, and car alarms set off by the blasts blared for hours.

The toll in three days of clashes rose to 73 killed in Lebanon and at least 12 Israelis, as international alarm grew over the fighting and oil prices rose to above $78 a barrel. The U.N. Security Council held an emergency session on the violence, and Lebanon accused Israel of launching "a widespread barbaric aggression."

In addition to the fighting in Lebanon, Israel pressed ahead with its offensive in the Gaza Strip against Hamas, striking the Palestinian economy ministry offices early Saturday.

In another maritime strike, Israel said that a Hezbollah rocket barrage missed its target and struck a civilian merchant ship. They did not know the nationality of the ship, or whether there were casualties.

The ramming of the Israeli missile warship indicated Hezbollah has added a new weapon to the arsenal of rockets and mortars it has used against Israel. The Israeli army said the ship carrying several dozen sailors suffered severe damage and was set on fire. Several hours after the attack, the fire was put out and the ship was being towed back to Israel. The military confirmed news reports that four sailors were missing and said a search for them was under way. -->