The official was not authorized to speak publicly.
"The IDF is on high alert and is constantly monitoring the operational situation," the Israeli military said. The IDF said fighter jets and navy vessels are "on a defense mission in Israeli airspace."
Dozens of drones were launched and could take hours to arrive, according to Israel's top-rated Channel 12 TV news. Retired general Amos Yadlin told the channel the drones were equipped with 20 kg of explosives. Israel's military said sirens will sound in any threatened areas.