Iran's Islamic Revolutionary Guard Corps (IRGC) has fired off missiles as well as drones towards Israel, according to an IRGC statement.
The attack comes in "response to the recent crimes of the Zionist regime", according to the statement.
Earlier, the Israel Defense Forces (IDF), Iranian state media and the US all confirmed the attack that began on Saturday evening.
Israel has shut its airspace overnight due to the attack, Israeli media reported, citing the aviation authority.
"We are closely monitoring Iranian killer drones that are en-route to Israel," an IDF spokesman said. "This is a severe and dangerous escalation."
He said Israel's defensive and offensive capabilities are at the "highest level of readiness ahead of this large-scale attack from Iran."
US President Joe Biden was being kept informed of the situation and was to meet with his security team at the White House for talks, a spokeswoman for the National Security Council said.