The Lebanese Shia Muslim militant group Hezbollah has fired several anti-tank rockets into northern Israel in retaliation for a reported Israeli drone attack in Beirut last week.
Israeli military sources confirmed rockets had been fired at an Israeli army base and military vehicles.
The Israeli army responded by attacking targets in southern Lebanon.
Hezbollah sources reported several Israeli casualties, but Israel said no-one had been injured on its side.
The Lebanese military earlier said an Israeli drone had entered its airspace and dropped incendiary material on a forest along the border.
The Israeli army has acknowledged it started a fire. Tensions on the frontier escalated in recent days.
Hezbollah, which is backed by Iran, has threatened to carry out an attack against Israel.
It accuses Israel of trying to carry out a drone attack in Lebanon’s capital Beirut last week.