The Israeli army and Hezbollah’s Shiite Lebanese militia fighters exchanged fire across the border.
An IDF spokesperson said there was “ongoing fighting” in the Mount Dov area, part of the Syrian Golan Heights occupied by Israel.
He said there were no Israeli casualties. There has been no official word on Lebanon’s injuries.
The area has been tense for days after a Hezbollah fighter was killed in an alleged Israeli airstrike in Syria.
Israel, which has neither confirmed nor denied leading the strike in the early hours of last Monday, warned Hezbollah not to retaliate.
The IDF said “three to four” militants entered Israeli territory but fled after Israeli forces fired at them.
Israel and Hezbollah are bitter enemies who waged a month-long war in 2006 after Hezbollah killed eight Israeli soldiers and kidnapped two in a cross-border raid.
The ensuing conflict killed some 1,191 people – mostly civilians – in Lebanon, and 121 soldiers and 44 civilians in Israel.