Israeli media quoted a security source as threatening that "Beirut will shake today," after 10 Israelis were wounded by Hezbollah rockets in the Tel Aviv region and northern Israel.
Air raid sirens were activated in several areas of central and northern Israel on Sunday, the army said, after projectiles were fired from Lebanon.
The sirens sounded in "a number of areas in central Israel" and in different parts of the country's north, the military said.
It added in separate statements that 18 projectiles crossed from Lebanon towards central Israel, while around 30 projectiles were "identified crossing from Lebanon into Israeli territory" in the north.
Some of the projectiles were intercepted, the army added.
Israel's emergency medical service Magen David Adom said it had provided treatment to two people including a 70-year-old woman who was slightly injured.