A missile fired by Hezbollah, not an unmanned drone laden with explosives, damaged an Israeli warship off Lebanon, the army said Saturday.

The attack on Friday night had raised widespread concern in the Israeli military because initial information indicated that the guerrillas had used a drone for the first time to attack Israeli forces.

But the army's investigation into the attack, which left four Israeli sailors missing, showed that Hezbollah had fired an Iranian-made missile at the vessel from the shores of Lebanon, said Brig. Gen. Ido Nehushtan.

"We can confirm that it was hit by an Iranian-made missile launched by Hezbollah. We see this as very profound fingerprint of Iranian involvement in Hezbollah," Nehushtan said in an interview with The Associated Press.

Another Hezbollah missile also hit and sank a nearby civilian merchant ship at around the same time, Nehushtan said. He said that ship apparently was Egyptian, but he had no other information about it.

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Nehushtan said the body of one of the four Israeli soldiers left missing by the attack on the warship was found aboard it, but other Israeli military officials said two bodies had been found.

Israel launched its offensive after Hezbollah guerrillas crossed the Israel-Lebanon border on Wednesday and captured two Israeli soldiers. Israel has bombarded Lebanon's airport and main roads in the most intensive offensive against the country in 24 years, while Hezbollah has launched hundreds of rockets into Israel.

The intense fighting has sent shock waves through a region already traumatized by Israel's battle against Hamas militants in the Gaza Strip. With Israeli officials pointing fingers at Hezbollah's close allies, Syria and Iran, the crisis could soon spread even further.

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The damaged Israeli warship, which had been carrying several dozen sailors, was traveling back to the Israeli port of Haifa on Saturday after a fire aboard it was put out.

Initial reports about a drone having carried out the attack on the Israeli warship would have indicated that Hezbollah has added a new weapon to its standard arsenal of rockets and mortars, and could draw Iran even closer to the conflict. Hezbollah reconnaissance drones have entered Israeli airspace twice in recent years. In those instances, Israel accused Iran of providing the drone technology to the guerrilla group.

A video purportedly showing the Israeli warship hit by Hezbollah was aired on the guerrilla's Al-Manar TV station Friday. The video aired nighttime pictures of an object flying over a city and falling in the distance and exploding. The footage was unclear and did not clearly show what the hit target was.

"The real occupying power in Lebanon is terror — terror instigated by Hezbollah but funded by Iran and Syria," Israel's U.N. ambassador, Dan Gillerman, said at an emergency Security Council meeting Friday.

During the current campaign, Hezbollah has proved to be a tough foe. Despite numerous airstrikes on Hezbollah targets, including the headquarters of its leader, Sheik Hassan Nasrallah, Israel has been unable to stop the rocket fire.

Nine Israeli soldiers and four civilians have been killed in the fighting, and the loss of the three sailors threatened to drive the death toll higher. At least 73 Lebanese have died, most of the them civilians.

Some 500,000 Israelis were ordered to stay indoors and away from windows Friday night as a precaution against the rocket fire. Residents in northern border communities were ordered to sleep in bomb shelters, which are found in virtually every Israeli home and apartment building.

Israel's army chief said Friday that Hezbollah has rockets that can reach as far as 70 kilometers (45 miles), a dire warning that more Israeli cities could be subject to attacks.

"Hezbollah used, until now, mostly rockets with a range of about 30 kilometers (20 miles)," Halutz said. "They have missiles with a range of 70 kilometers (45 miles), or maybe more."

That means well-known cities and tourist attractions like Nazareth and Tiberias on the Sea of Galilee, and the central city of Hadera could be in striking range.

On Thursday Hezbollah fired two rockets at its deepest destination in Israel so far, the city of Haifa, home to Israel's largest passenger ship port, major oil refineries and several key industrial installations. Haifa is about 40 kilometers (25 miles) from the Lebanese border.

Since the offensive began, more than 300 rockets have hit northern Israel, the military said.