A hostile aircraft entered northern Israel from Lebanon, the Israeli military said on Wednesday night, urging residents there to stay inside shelters.
The Israeli military reported in a statement "a suspected infiltration from Lebanon into Israeli airspace", but did not specify which kind of aircraft, Xinhua news agency reported.
Sirens warning of "hostile aircraft" were heard across the Galilee region and the Israeli-annexed Golan Heights, it said.
"All civilians in the areas where sirens were sounded are asked to enter shelters and stay in them until further notice," the statement added.
Israel's state-owned Kan TV news reported that about a dozen drones had entered, and Israeli aircraft were chasing them in an attempt to intercept them. Video footage on social media showed a drone flying in the cloudy skies of northern Israel.
Israel's Magen David Adom rescue service said that no casualties had been reported.