Lebanese and Israeli soldiers exchanged cross-border fire Wednesday, but no casualties were reported.
The Lebanese army says its soldiers opened fire on an Israeli bulldozer that crossed the border. The Israeli army says its soldiers returned fire.
The Israeli forces were searching for explosives along the border, after discovering four bombs there Monday.
The Shi'ite militant group Hezbollah says it did not recently plant the bombs. Hezbollah officials said Tuesday that the bombs were placed before last year's war between Israel and Hezbollah.
Israeli officials have said they believe the bombs were placed in recent days under the cover of fog and rain.
If Hezbollah is responsible for placing explosives in recent days, it would mark a violation of a U.N.- brokered ceasefire agreement declared last August.
In July 2006, Hezbollah abducted two Israeli soldiers in a cross-border raid, which started a month-long war between Israel and the militia.
Some information for this report was provided by AP and Reuters.