An Israeli solder in Lebanon

Israeli ground forces are on the move early Thursday in southern Lebanon.

Witnesses say Israeli tanks and armored vehicles have pushed at least seven kilometers into Lebanon. Israeli troops were reported to be battling Hezbollah fighters.

The Israeli military says the advance does not mark the major extension of ground operations approved Wednesday by Israel's Security Cabinet. Israel says its forces are targeting Hezbollah positions in the town of Khiam that fired more than 60 rockets into Israel Wednesday.

This comes after Hezbollah leader Sheikh Hassan Nasrallah vowed in a televised address to turn southern Lebanon into a "graveyard" for Israeli troops.

Meanwhile, the Israeli army says 15 Israeli soldiers were killed and 38 wounded in clashes with Hezbollah in southern Lebanon Wednesday, the bloodiest day for Israel in four weeks of fighting the guerrilla group.

At least 30 Hezbollah fighters were killed.

In his televised address, Sheikh Hassan Nasrallah also urged Arabs to leave Israel's northern port city of Haifa, which has been hit by Hezbollah rockets during the current offensive.

Israel's Security Cabinet agreed Wednesday to send troops as far as 30 kilometers into Lebanon, to the Litani River.

At least 900 Lebanese and 100 Israelis have been killed in fighting that began after Hezbollah guerrillas captured two soldiers in Israel July 12.

Some information for this report provided by AP, Reuters and AFP.