Israel shelled south Lebanon after an explosion near the border wounded two Israeli soldiers.
The Israeli military said two soldiers on border patrol Tuesday were wounded when an explosive device went off near Shebaa Farms, which is also close to the Syrian border.
Lebanon's Shi'ite Hezbollah movement has claimed responsibility for the bomb attack.
Earlier border breach
Earlier this week, Israeli troops shot and wounded a Lebanese soldier in the same area, after what the Israeli army called a border breach.
Lebanon's military countered that an army outpost came under Israeli fire, lightly wounding one soldier.
Israel and Lebanon have been in conflict since 1948. Clashes occasionally punctuate a cease-fire.
The border area has remained largely quiet since a month-long war in the summer of 2006 between Israel and Hezbollah guerrillas in Lebanon.