The Israeli army told 3,000 reserves to report for duty, an Israeli military source said on Friday, a day after Amir Peretz, the defence minister, refused to rule out a land offensive.
Peretz said: "There is no intention of occupying Lebanon, but if certain things must be done, we will do them without hesitating."
However, after reports on Friday that an invasion was imminent, an Israeli military source said: "You should not expect a full-scale incursion into Lebanon."
The source said that targeted incursions along the border would intensify.
Brigadier-General Alon Friedman, who is in charge of army operations in the north, said: "It's possible that in the coming days our ground operations will increase."
Israel also dropped leaflets over Lebanese border villages warning civilian inhabitants to leave their homes before an Israeli offensive. Hundreds of thousands of people have already fled.
The YNET news website said that the Israeli army could have three to four divisions on the border with Lebanon by the end of the weekend, a report the army would neither confirm nor deny.
Elite Israeli troops have already been launching small-scale raids in Lebanon to try to stop Hezbollah rocket attacks but the government is wary of a full-scale invasion, only six years after it ended a costly 22-year occupation of the south.
Meanwhile Lieutenant-General Dan Halutz, the head of the Israeli military, said his forces had killed nearly 100 Hezbollah fighters in Lebanon during the 10-day offensive.
A new poll in the Maariv newspaper showed Israelis still overwhelmingly back the military operations.Hezbollah rockets
Israel says that its air attacks aim to prevent Hezbollah launching more rockets at Israeli cities.
It is an aim yet to be achieved as the resistance group launched more rockets at Israeli towns and cities on Friday morning.
Hezbollah has fired more than 900 rockets at northern Israel, killing 15 civilians. 19 Israeli soldiers have also been killed in the conflict.
Three missiles landed in Haifa, Israel's third-largest city, wounding at least 19 civilians.