Eleven people, including six children, were killed in Israeli attacks on villages across southern Lebanon, a hospital director and three Lebanese security sources said.
Israel said it responded to a Hezbollah rocket attack that killed one of its soldiers.
A woman and her two children were killed in an Israeli attack on the village of El Savana, two security sources said.
Four more children, three women and a man died in the attack on the building in Nabati, and according to the director of the city hospital, Hasan Vazni, three other sources also died.
Four Hezbollah fighters were killed in separate attacks, the group said.
Hezbollah and the Israeli military have been exchanging fire along the Israeli-Lebanese border for more than four months, after the Lebanese armed group launched rockets across the disputed border in a show of support for its Palestinian ally Hamas.